<em>Radioactive tracers are useful in </em><em><u>determining medical problems.</u></em>
Answer: <em>B. Determining medical problems.</em>
Explanation:
Radioactive tracers are comprised of carrier particles that are reinforced firmly to a radioactive atom. These bearer particles shift incredibly relying upon the motivation behind the scan.
A few tracers utilize atoms that associate with a particular protein or sugar in the body and can even utilize the patient's very own cells.
Examples of radioactive tracer are - tritium, carbon-11, carbon-14 and oxygen-15 and so forth. Radioactive tracers are either injected in the body intravenously or orally.
Energy from the sun is transferred to Earth's surface. Some of that energy is then transferred to the air above the surface. The closer a location is to the equator, the more energy it receives from the sun. Therefore, a location's air temperature is affected by its distance from the equator.