Both in aerobics and dancing there is a lot of excercise going on...like salsa dancing, ballet, and break dancing...you use a lot of muscles jumping, twirling, and repetitions.
I would say A. The three other choices could lead to its start.
60 to 100 beat in a minuto.
Basically, your thumb is the only part of your body that has saddle joints. the bones in your saddles joint is responsible for moving back and forth, side to side. these joints are free enough to make any motion in your body. They are the only joints that can do 360 degrees and rotate with their own axis. But, because of its free moving, it is prone to any dislocation compared to other movable joints.
Fast reaction time, speed
