B is the answer to your question.
The answer is letter A.
In the evolutionary sense fitness refers to the measure of reproductive success of an individual or of organisms in general. Those organisms that leave the largest number of mature offspring are the fittest. Fitness can be achieved through survival or mortality selection, mating success or sexual selection, and family size or fecundity selection. Fitness is critical for a species’ survival and is a major adaptation that all organisms do through a long period of time.
crude oil is composed of B. Hydrocarbons
The answer for the blank is RESSESIVE