Well, the food is in the environment. I would like to compare it with how bacteriae feed (however my biology is quite rusty), that is, they engulf their food and they "digest" -- not the proper term, since there are no organs to do real digestion -- it.
The correct answer is option C, that is, behavioral isolation.
The phenomenon of behavioral isolation takes place when two populations possess the tendency of interbreeding, but exhibit distinctions in courtship rituals or other kinds of behavior. For example, the western and eastern meadowlarks are very identical birds whose habitat overlap in the middle of the United States.
However, the members of the two species will not mate with each other, possibly as they use different songs in order to fascinate males. The eastern meadowlarks will not respond to the songs of western meadowlarks, and vice versa.
There are three processes of aerobic cellular respiration; glycolysis, the Kreb's cycle and the electron transport train. The electron transport train synthesises the most ATP.
