Answer:
it is not mri it is Electroencephalography (EEG)
Explanation:
whitch is B
A, because in all, stretching is to reduce muscle tightness and relax muscles. It also can be used as a warm up for sport activities, like a jog, or running a mile, etc.
It's also used a stretch warmup by P.E. Teachers sometimes. If you search up dynamic stretching it shows many stretches, and people do these all the time to prepare for exercise, or to loosen up tight muscles.
So its acquired immunity and the cells responsible are the B lymphocytes that produces antibodies against the virus. Memory is keep since first encounter of the virus by the immune system by way of the antibodies that was initially produced. The antibodies are there already, which makes it fast to act upon when expose again.
