What is aerobic exercise? A.
Exercise that uses large muscle groups to move your body
B.
Exercise that uses small muscle groups to move your body
C.
Exercise that refines small muscles through small but intense movements
D.
Exercise that refines large muscles through small but intense movements

"Aerobic" is defined as "relating to, involving, or requiring free oxygen", and refers to the use of oxygen to adequately meet energy demands during exercise via aerobic metabolism. Aerobic exercise is performed by repeating sequences of light-to-moderate intensity activities for extended periods of time.

Explanation: i think it's A but tell me if im wrong

which ever one is showing doing the same exercise in time intervals such as 30 seconds or a minute several times.