How has agriculture contributed to the decline of the Chang Jiang's water quality?

A Clearing land for farming has caused acid rain.

B. The fertilizers used by farmers contaminate the river.

C. Livestock drink from the river and spread their diseases.

D. Irrigation of farmland has reduced the water level in the river.

Statement B is the correct answer

Explanation:

This is because answer choices A and D are completely incorrect as neither of these things could even relatively true. Then answer choice C could be viable although there would be a lot of questions to ask before determining if this answer works in the context of the situation, therefore, since it is a contextual choice the only one left is B.

Pro Tip: In problems like this where there is no stimulus, or context included in the question, all situational answers such as answer choice "C" can be eliminated.

the answer to the question is punishment. or more specifically, positive punishment.

positive punishment occurs when a behavior is given a negative consequence for the individual doing the behavior.

sara no longer wants to ask questions (the behavior) because she is ridiculed by mr. smith (the punishment).

reinforcement is inaccurate because reinforcement always gives positive consequences for the individual doing the behavior, be it by introducing a pleasant consequence or removing an unpleasant one.