Respuesta :
The answer is D because it sounds like the most ethical answer. The other choices are wrong because the could possibly hurt someone or an animal.
Answer:
D.) Research on animals in which the animal experiences no fear or pain.
Explanation:
It is ethical to perform test on an animal such that the animal experiences no fear or pain.
It is unethical to perform test on an animal when some other tests can be performed without the animal to get the desired results.
Polluting the water resource with contamination is an unethical practice.
People who are vulnerable cannot be subjected to experiments.