Read the following passage and questions, then choose the right answer from options, the answer should be one of A, B, C, D.

<passage>:
returned, and settled down to live. Saddened, but resigned and content to live in peace with his knowledge and his power. Gone now are all the ancient evils, wars, emergencies. Maternite Machine, it appears, has been drunk. The heat rose above the warning, continued to rise, and then—poof. Everything has evaporated in Maternite. All the Prelife is gone." "All of it?" I asked. "There is nothing left," Melia insisted. "Can more be made? And if not, what will happen with no more children?" "That is for the priests to say, not I," I replied. In moments of emergency, it is wise to speak with caution. That is, I suppose so. I They are of an age to enter manhood, and have all the energy such young men do. that they stood in the midst of an unprecedented happening indeed, an emergency. For a machine had failed! Not in the memory of the eldest among us has a machine failed. They were created so long ago, indeed, that the ignorant believe them to have been constructed by the gods themselves. And never, so far as I know, has one failed. Small wonder that the watcher had been negligent. Indeed, the watcher is more a tradition than a necessity. He rambled through the customary opening remarks and then, continually smoothing his white beard—of which he is excessively proud—approached the crux of the matter and the Conclave finally heard the facts it had assembled to hear. By this time, unfortunately, many of the Conclave had departed for home and supper. Yet perhaps it is for the best, for those left were the most earnest and intelligent. "I would not bore you," he said, "with details of which only the gods are sure. Know, then, that once granted a few cells of Prelife, it is an easy matter for the Maternite Machine to add more and more thus assuring us, as has always been, a continuous source of Prelife to be born by the Generating Machine as children. The machines bear the exact number of children each year to balance the number of us whom the gods claim. Such it has always been from time immemorial." A murmur of assent and approval of these virtuous words whispered around the Hall. Indeed, I might call it an emergency. For the M-Maternite Machine has the priest had I not been able to insure order. "That is not the worst," he cried, as if in defiance. "All the Prelife has been dried up. It will not function. There is no more. And there will be no more children!" At this I feared the Conclave was about to riot. It is at such times that I most revere the wisdom of the ancients, who decreed seventy years the minimum age for a member of the Conclave. They shouted and began to beat their fists, but for how long can a man of seventy years roar like a youngster? They quieted, breathing heavily, and I asked, "Is there no way, then, to produce more Prelife in order that the machines may produce more children for us? "As I have said," he replied, "give the machines but a bit of Prelife and they will produce more. But take away that least bit, and they are helpless." think. Rocsates leaned forward and asked, "Must there not—must there not have been a beginning to Prelife? For the Machine, it seems, cannot make it and yet it came from somewhere." "Riddles are not called for," I answered severely. "Are not riddles often the beginning of knowledge?" he asked, in that irritating dumber-than-thou attitude of his. "Must there not, long ago, have been a source of Prelife: a source now forgotten? And may it not thousands of years ago, time without reckoning, there existed on the earth creatures who were alive like us, and yet not like us. It is said indeed exist. It is recorded most scientifically in the films." "If it be so," I said, quieting the hub-bub that followed, "and I would not doubt your word, Rocsates, for all know you are the wisest of to such creatures. And indeed, if they had Maternite Machines, why then we would yet have these animals among us." "And how, then, did these animals reproduce?" I asked. "How, indeed? And is there not a legend—admitted only a legend—that says there was a time before the machines, and before the Maternite Machine, and that at such a time both the animals and Men reproduced from within their own bodies?" At this two members of the Conclave fell immediately into a faint, and I would gladly have joined them. I hoped that the youngsters, Xeon "I should like to ask the Conclave for permission to search the ancient and so delicate, that they are kept in an air-tight tomb lest, being handled, they be destroyed and all knowledge within them lost. Therefore, they have not been read in the known history of our race. Several weeks elapsed before Rocsates requested that the Conclave meet. I called the meeting at dawn and so it was yet early in the afternoon when formalities were concluded and Rocsates granted leave to speak. "Some of those among you are She's," he began. "And you know you are many books, and while they are all vague on the subject, this I have discovered: "That there was indeed a time before the machines, in fact the books Then reproduction was carried on by individuals, without help of the then nonexistent machines. The She's are not wanderers from another land, but they have lived with us for all time they are not another race, but we are all types of one race. And the fact of reproduction is reproduction must have been a pleasant thing to do otherwise they would not have done so to excess. And if it was a pleasant thing to do, where is the necessity for the machines, and why were they created?" with Melia were at the Conclave without permission, shouted, "Perhaps the process of reproduction was of such a pleasure that the Conclave At this impudence the Conclave dissolved in an uproar, and I was beyond they cannot do until they meet again. I needed a sufficient excuse to call a meeting of the Conclave, desired audience, I immediately proclaimed a meeting of the Conclave to be held the next day at dawn, and so that night slept well. The Conclave had come to order and formalities had been initiated when formalities were over. I intended to speak for Xeon, but Rocsates was on his feet and I gave way. "I have indeed discovered the secret of reproduction," he began. "After but it seems to mean...." His words trailed off. He was obviously unsure of how to continue. "I had better start at the beginning, I When he finished the Conclave sat in horrified silence. His words, to move. I cleared my throat. "Shall not these organs which you mention have atrophied by now? With no use throughout all these generations, will they not have evolved into nothingness?" "I do not think so," Rocsates replied after a while. "What to us is an eon, to evolution is but an instant. And then the swelling of the breasts, I believe, proves that there is still reproductive activity in some, at least, of the She's." I voiced my assent, and the entire Conclave adjourned to the fields. "They may indeed have succeeded," Rocsates replied. "There is mentioned a time lapse which is necessary. The child does not appear immediately." "It doesn't matter," I said disconsolately. "Who could ask them to go through such an ordeal again?" And then I looked down to earth again, and saw them standing before me. "Sias, we come to tell.... We will...." He raised his eyes to mine and said manfully, "We shall try again." I am afraid that tears came to my eyes. Such sacrifice— I watched them turn and wander off together under the stars. My heart has a warmth in it, and I no longer fear for the future of our race when our young people can show such nobility and sacrifice.

<question>:
Why does Sias believe that the ancients declared 70 as the minimum age for a member of the Conclave?

<options>:
A They are the ones who remember things from previous generations that get lost to time
B They do not have the energy to riot amongst themselves
C They are closest in lineage to the predecessors that generated the machines
D They have had sufficient life experience at that point

<answer>:

B