Which of the following would be most useful for detecting the brain areas that are most active as a person performs mathematical calculations? a. a brain lesionb. an interneuronc. a pet scand. a hemispherectomy

The answer is; C

A PET scan is a positron emission tomography used to image the inside of the body. It involves the ingestion of a radioactive element. The element is actively absorbed by the tissue with active cellular activity hence these areas will show as bright spots when the body (this case the brain) is scanned.

i'd say that the moon rock is about 2.2 billion years old.

is this a psat question, if so do not cheat try your best.