The swallowed food moves downwards in the alimentary canal because of
A
The flow of water taken with the food.
B
Force provided by the muscular tongue.
C
The contraction of muscles in the wall of food pipe.
Correct option is D. The contraction of muscles in the wall of food pipe.
When food goes into the food pipe, the muscles in its walls start alternate contraction and relaxation producing a wave-like movement that called 'peristalsis'. These movements are necessary for forwarding the food downwards in the alimentary canal.
The correct answer is option (d).