The correct answer is A. Biomagnification
Explanation
Biomagnification is a term used to refer to the process of accumulation of chemicals, pollutants and similar in the body of different organisms across food chains. This occurs as the amount of nocive substances increases their concentration as the trophic levels are higher. For example, when some chemicals contaminate a river, first acts against plants or the food of the fishes, later fishes acquire the contamination, after that other animals as humans consume fishes and they are exposed to chemical contamination in greater quantity. So, the correct answer is Biomagnification.