The answer is D this help flex the neck and rotate the head upwards and side to side.
Answer:
option d. Hypertrophy and neural facilitation.
Explanation:
Strengthening of muscles or say the capacity to generate force of muscles can be improved by training the muscles with the help of neural facilitation and hypertrophy.
Neural facilitation is the process that transfers the stimuli to the muscles
To overcome the deficiency of oxygen during training of muscles, the muscles grow in size. this phenomena is termed as Hypertrophy.