Answer:
C.
Step-by-step explanation:
Based on the answers provided it can be said that the main response of the force of gravity on land animals is that is caused them to have a rigid musculoskeletal system. This is because the Earth's gravity provides the needed help for land animals to maintain their muscle mass, mainly due to Earth's pull putting stress on the skeletal system, which helps keep it sturdy and rigid for the animal to be able to move appropriately.