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

<passage>:
delivered a paper entitled simply, "On the Nature of the Solar Niemand by Philip Latham. LATHAM. What do you mean by activity on the Sun? NIEMAND. Well, a sunspot is a form of solar activity. LATHAM. Just what is a sunspot? NIEMAND. I'm afraid I can't say just what a sunspot is. I can only describe it. A sunspot is a region on the Sun that is cooler than its LATHAM. Isn't it true that the number of spots on the Sun rises and NIEMAND. The number of spots on the Sun rises and falls in a cycle of NIEMAND. It means you can only approximately predict the future course of sunspot activity. Sunspots are mighty treacherous things. sunspots and various effects on the Earth? NIEMAND. Scores of them. NIEMAND. Pure bosh in most cases. NIEMAND. A few. There is unquestionably a correlation between sunspots and disturbances of the Earth's magnetic field ... radio solar and terrestrial relationships along rather unorthodox lines. NIEMAND. Yes, I suppose some people would say so. NIEMAND. That's true. NIEMAND. I think our biggest advance was the discovery that sunspots themselves are not the direct cause of the disturbances we have been NIEMAND. We had to call them something. Named after the Sun, I suppose. NIEMAND. It is quite invisible to the eye but readily detected by observed. LATHAM. Just what are these effects? NIEMAND. Well, they're common enough, goodness knows. As old as the world, in fact. Yet strangely enough it's hard to describe them in exact ourselves but in our stars" or better "in the Sun." LATHAM. In the Sun? NIEMAND. That's right, in the Sun. I suppose the oldest problem in the NIEMAND. Consider the record of history. There are occasional periods NIEMAND. What reasons? NIEMAND. Perhaps I'd better go back to the beginning. Let me see.... It depression, anxiety, insomnia, alternating with fits of violent rage and resentment against life and the world in general. These people were fit into this picture. They were married and single persons of both sexes and of all ages. They came from all walks of life. The onset of their attack was invariably sudden and with scarcely any warning. They ten days later the attack would cease as mysteriously as it had come and NIEMAND. Oh, yes. In a few cases in which I tried tranquilizing pills of NIEMAND. It was the beginning. In most instances patients reported the symptoms were usually slight ... a sudden feeling of uneasiness and for a long time getting absolutely nowhere. Then finally a pattern began LATHAM. What sort of pattern? NIEMAND. The first thing that struck me was that the attacks all occurred during the daytime, between the hours of about seven in the morning and five in the evening. Then there were these coincidences— LATHAM. Coincidences? NIEMAND. Total strangers miles apart were stricken at almost the same moment. At first I thought nothing of it but as my records accumulated I analysis showed the number of coincidences followed a Poisson distribution very closely. I couldn't possibly see what daylight had to do with it. There is some evidence that mental patients are most disturbed around the time of full moon, but a search of medical literature failed to reveal any connection with the Sun. NIEMAND. Naturally I said nothing of this to my patients. I did, simultaneous attacks of rage and depression all over southern occurred to me: if people a few miles apart could be stricken simultaneously, why not people hundreds or thousands of miles apart? It was this idea that prompted me to get in touch with an old colleague of NIEMAND. I was afraid the result would be that my old roommate would NIEMAND. We say an attack is simultaneous when one occurred on the east NIEMAND. In every case of a simultaneous attack the Sun was shining at NIEMAND. No, no. The weather had nothing to do with it. I mean the Sun attack soon after sunrise in New York but there would be no Conversely, a person might be stricken late in the afternoon in set. Dr. Hillyard and I had been searching desperately for a clue. We had both noticed that the attacks occurred only during the daylight hours but this had not seemed especially significant. Here we had evidence pointing directly to the source of trouble. It must have some connection with the Sun. NIEMAND. It was the old case of workers in one field of science being astronomers have gotten so used to hearing from flying saucer enthusiasts and science-fiction addicts that nothing surprises them any NIEMAND. It was really quite simple. But if it had not been for When Middletown had finished it was easy to see that the squares of straight lines down through them. The connection with the Sun was NIEMAND. Why, because twenty-seven days is about the synodic period of solar rotation. That is, if you see a large spot at the center of the Sun in a way that was even more convincing. NIEMAND. I said that the lines drawn down through the days of greatest mental disturbance slanted slightly. On this second chart the squares at intervals of twenty-seven point three days. NIEMAND. Because the average period of solar rotation in the sunspot correlation with the synodic rotation of the Sun was practically NIEMAND. Middletown was immediately struck by the resemblance between the chart of mental disturbance and one he had been plotting over the the resemblance between the two was unmistakable. The pattern shown by the chart of mental disturbance corresponded in a striking way with the solar chart but with this difference. The disturbances on the Earth started two days later on the average than the disturbances due to the S-Regions on the Sun. In other words, there was a lag of about he detect them? NIEMAND. The S-Regions are invisible to the eye through an NIEMAND. Very closely. You see it takes about twelve days for an S-Region to pass across the face of the Sun, since the synodic rotation NIEMAND. Apparently an S-Region is not particularly effective when it is just coming on or just going off the disk of the Sun. LATHAM. Are the S-Regions associated with sunspots? NIEMAND. They are connected in this way: that sunspot activity and S-Region activity certainly go together. The more sunspots the more one-to-one correspondence between sunspots and S-Regions. That is, you cannot connect a particular sunspot group with a particular S-Region. The same thing is true of sunspots and magnetic storms. NIEMAND. We don't account for it. NIEMAND. Middletown says that the radio waves emanating from them are NIEMAND. We doubt it. As I said before, the charts show a lag of about NIEMAND. Our latest results indicate that probably NIEMAND. An S-Region may have a lifetime of from three to perhaps a dozen solar rotations. Then it dies out and for a time we are free from NIEMAND. Because the radio exploration of the Sun only began since the enough numbers to attract attention. Also the present sunspot cycle NIEMAND. I'm afraid the only sure way is to keep on the unilluminated sharply defined, since its effects are felt simultaneously over the NIEMAND. At the present moment there happens to be no S-Region activity on the Sun. But a new one may develop at any time. Also, the outlook for a decrease in activity is not very favorable. Sunspot activity continues at a high level and is steadily mounting in violence. The last sunspot NIEMAND. That is the logical outcome of our investigation. We are NIEMAND. The trouble is they seem to develop at random on the Sun. I'm NIEMAND. If you have a feeling of restlessness and anxiety, if you are

<question>:
In observing the sunspot-related disturbances, what pattern did Niemand notice? What pattern did Niemand notice of the disturbances? (daytime, strangers)

<options>:
A They occurred during the daytime and among complete strangers
B They occurred during the daytime and among peers or those with mutual contacts
C They occurred during the nighttime and among complete strangers
D They occurred during the nighttime and among peers or those with mutual contacts

<answer>:

A