I think the answer is D but it's been a while since I've done this.
There are three types of energy involved in a muscle's contraction. There is metabolism, catabolism, and anabolism. Metabolism is the events that are carried out in the human body to create energy and other things needed for activity. Catabolism is the process during the organic matter is broken down and the energy is released, it takes place during increased movement. Anabolism is the energy-consuming process that substances are created, it takes place when there is little movement. All three of these work to gather in muscle contraction.
Natural selection doesn't favor traits that are somehow inherently superior. Instead, it favors traits that are beneficial (that is, help an organism survive and reproduce more effectively than its peers) in a specific environment. Traits that are helpful in one environment might actually be harmful in another.
(one again, I hope this helps ^^)
C. The associates proteins are histones
I can help you... what do you mean?