Movement of snake is helped by

The correct option is A Muscles

Snakes are devoid of organs of locomotion. They move by contraction and relaxation of muscles. They have different types of movement like serpentine movement, caterpillar or reticular movement, sidewinding movement and concertina movement.

Serpentine movement is a type of movement which starts from the head, the snake will contract their muscles, thrusting their body from side to side. This movement creates a series of curves.

So, the correct answer is option A.