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

<passage>:
to “cook” in an atomic reactor and soak up radioactivity. 33 “We weren’t planning to run a submarine with it,” his father said. “It wasn’t that strong. Still, it doesn’t take so very much radioactivity to make two ounces of an isotope quite powerful—and quite deadly. I only hope whoever stole it knows what he’s doing. However, I’m sure he does.” scientist himself?” Eddie asked. “Let’s just say he—or both of them—have enough training in the subject to know how to handle that isotope safely,” Mr. Taylor said. door. they do with it?” “They could study it,” his father explained. “At least, they could send it somewhere to be all right if I use the Geiger counter today?” broken down and studied. Being a new isotope, the formula is of great value.” “What do you mean, send it somewhere?” “Then—then you mean whoever stole it “In fact, it’s the only logical explanation I can think of. People simply don’t go around stealing “You may use the Geiger counter any time radioactive isotopes without a mighty important rocks. Suddenly the Geiger counter began as good as another when it comes to hunting kitchen. it would take a magnifying glass to detect any small rubber bands from his tooth braces. what it’s all about if you could explain what a fill all the needs for radioactive materials. Besides, and dangerous to handle that it’s not a very good idea to try using it in its true form. one building holds the reactor itself. It’s the having to do with atomic science excited him. He knew something about isotopes—pronounced eye-suh-tope . You was a material which had been “cooked” in an When carefully controlled, the radiation stored up in such isotopes was used in around, but they break apart. They shoot out little particles called neutrons. These neutrons hit other atoms and split them apart, sending asking that particular question was to keep it to. They have ways of controlling it so that only as much radiation builds up as they want. “And Geiger counter?” Eddie asked careful tending, the scientists keep the atomic not actually using it.” “But the whole pile is covered by a shield of concrete about eight feet thick. That keeps the rays from getting out and injuring the workmen.” “Goodness. Eight feet is a lot of cement.” particles,” Eddie explained. “Especially the had provided during the earlier hours. gamma rays. They’re the fastest and most dangerous, to the house and getting the Geiger counter and the hardest to stop. Alpha and beta rays are fairly easy to stop. But the gamma rays are regular high-velocity invisible bullets. They’ll go right through a stone wall unless Not with even the most powerful microscope in the world.” it’s plenty thick. Of course, you can’t see them. where I might get shot at by—by dangerous 39 protected. They see to that. Well, anyway, scientists take certain elements which aren’t radioactive, but can be made radioactive, and shove small pieces of them into holes drilled with a Geiger counter. 18 “They don’t shove them in with their bare hands,” Eddie said, trying not to show exasperation. “They use long holders to push the small chunks of material into the holes in the reactor. Then, as those uranium atoms keep will soak up radiation, just like a sponge “I’ve seen them do it,” Eddie said proudly, then added, “from behind a protective shield, of course. When the material has soaked up enough radiation, they pull it back out. They say it’s ‘cooked.’” came out of a stove. By hot, they mean it’s a radiation burn. That’s a kind of burn you said. “It’s like a sponge. Only instead of soaking watch me do a little prospecting with the Geiger counter. But maybe you’re too busy.” that as more is learned about the ways to use isotopes, the whole world is going to be improved. You’ve heard of radiocobalt for curing cancer. Well, that’s an isotope. They make it Some soak up a lot of radioactivity, and are strong and dangerous. Others absorb only a little and are pretty safe to use. Depends, too, “What kind was the one stolen from the the kitchen. He felt triumphant about the “except he did say that if whoever took it even the mild isotopes are deadly if they’re not handled right.” “My goodness, it is a serious matter, isn’t than its threat of danger to anyone who secret isotope. His father hadn’t said whether it had been developed for curing things or for used. Eddie assumed that anyone who would stoop to stealing isotopes more than likely would be interested in their ability to destroy rather than their ability to benefit mankind. work.” “She always does, Mrs. Ross,” Eddie said, pretending great injury. “Don’t know why I “Well, I certainly do hope everything works it. After all, this is an atomic age. We might as well face it. My father says that in horse-and-buggy days everyone knew how to feed a horse and grease a wagon wheel. They knew what was needed to get the work done. But now that atoms are being harnessed to do the work, not mother glanced at the Geiger counter which many people even bother to find out what an atom is.” job of trying to feed a herd of them the size of a period,” he said. “Did you know that there Ross cautioned, as Eddie picked up the Geiger switched on the Geiger counter. The needle but Eddie knew these indicated no more than a normal background count. There were slight traces of radioactivity in almost all earth or rocks. It was in the air itself, caused by mysterious and ever-present cosmic rays, so there was always a mild background count when the Geiger counter was turned on mean anything, the needle had to jump far ahead on the gauge, and the clicking through “In fact, not good at all.” door. He put the Geiger counter in the closet “But this morning you said it would be driver was inquiring where to put it, the container isotope. His father had plenty on his mind, as it was. The main information was in the evening in his chair. 28 “They’ve got it pretty straight, at that,” Mr. Taylor said, “but I’m afraid this is going to defended. I am head of the department. I knew about the shipment. That should make it my responsibility to see that it was properly received and placed in our atomic-materials storage vault. But there is little point in trying to place the blame on anyone. I’m willing to accept it of a secret nature, but it is also dangerously radioactive if improperly handled.” “But—but wasn’t it in a safe container?” 29 “Of course,” his father said. “There were only two ounces of it in a fifty-pound lead capsule. As long as it remains in that capsule it’s safe. As you know, the lead prevents any radiation from escaping. Out of that capsule, however, those two ounces of radioisotope can be very dangerous.” shot. The whole thing was carefully planned and carefully carried out. It was not the work of amateurs.” had carried out the theft. A heavy iron pry bar had been dropped at the rear of the truck after the lock was sprung. It was a common type paper, “how could anyone carry away something weighing fifty pounds without being noticed?” “Chances are they had their car parked nearby,” his father said. “As you know, there automobiles parked around the shipping and the men know that the delivery truck would worked out, they didn’t need to use it. The expected. At least, they took quick advantage was a new one. A very secret one. Our job at the college was to conduct various tests with it in order to find out exactly how it could best be put to use as a cure for disease, or for sterilizing food, or even as a source of power.” “Power?” Eddie said. “Boy, it must have been a strong isotope.” He knew that the strength of radioisotopes could be controlled

<question>:
Given the information in the article, what is the purpose of a Geiger counter?

<options>:
A To measure rock formation patterns.
B To measure for radiation.
C To find hidden rocks.
D To measure gravity.

<answer>:

B