Answer:
B)compression
Explanation:
By carrying backpack can exert some severe pressure on the lower area of the body , i.e. , back and hips .
The straps of the bag are responsible to carry all the load and hence can lead to stress and strain in the upper area of the body , i.e. , shoulders , back and neck .
The excessive use of backpack for a long period of time , an make you pull backward due to the heavy load and therefore , in order to balance the force the body bends forward , which lead to the compression of the spin .
