The hot air when come to close cold air forced to increase its speed
Which makes monsoon and also thunderstorm perform
Answer
Option C - Skeletal Muscles
Explanation
Antagonistic pairs are the muscles that are functionally opposite, if one produces flexion, then the other's primary action is an extension. Skeletal muscles work in pairs to move a bone so that the muscles can function properly. They contract the bone making nerves deliver a message to the brain. For example. Biceps and triceps. The lower arm is moved upwards when the biceps muscle contracts and the triceps muscle is relaxed and vice versa.
The answer is D. The natural selection is a theory which illustrates the gradual process of evolution in the population due to the change of environment. The key point is the mutation (variation) exists in the population before the environment changing. For C, if the environment does not change, though the adaptation is useful to environment, it will not be selected. Because the organisms without the adaptation will not die.