The correct answer is (d) Skeletal muscles contract and pull the tendons to move the bones.
Explanation:
Skeletal muscles: These are the muscles responsible for voluntary movements like running and working. They are attached to bones via tendons.
Tendons: These are tough, fibrous cords that connect muscles to bones.
Contraction: When a skeletal muscle contracts, it pulls on the tendon attached to it, which in turn causes the bone to move.
Why the other options are incorrect:
(a) Smooth muscles contract and pull the ligament to move the bones:
Smooth muscles are responsible for involuntary movements like digestion and blood vessel constriction. They are not attached to bones directly and do not play a role in moving limbs. Ligaments connect bones to other bones, not muscles to bones.
(b) Smooth muscles contract and pull the tendons to move the bones:
As explained above, smooth muscles are not involved in bone movement. While tendons are involved, they are pulled by skeletal muscles, not smooth muscles.