Answer:
D. Raising and lowering the body with the elbows locked out in the up position and a flat back
Explanation:
Flexion is a classic and efficient exercise. This is a calisthenics exercise (which uses body weight) and one of the oldest and most popular, as it is easy to perform and can be performed in different places without the need for devices.
In addition, it is an exercise that can work several muscles. Generally, it is used in order to work the muscles of the chest, however, with some variations, we can give a greater focus to other auxiliary muscles. However, certain precautions are necessary when it comes to changes in flexion, for the change to be efficient it is necessary to raise and lower the body with the elbows locked in the upper position and the back flat.
