The Answer is A.The biceps muscle contracts while the triceps muscle relaxes. Only then can the forearm move up to lift the mug.
Doing a hip-hop dance class at the gym for five minutes three days a week is a good way to increase one`s heart rate; however, if Crystal wants to land in a heart rate zone between 142 to 180 beats per minute, then, she has to dance at a faster pace. Doing something at a faster pace would result in the heart pumping much faster in order to compensate for the needs of the body for that specific moment.
