Manuel approaches his psychology professor about the possibility of using rats to conduct a psychological study. his professor appropriately reminds him that if his use of animals is to be in accord with ethical principles, his research must have an acceptable scientific purpose and that he should expect it to:

The correct answer is increase understanding of the species under study.

When conducting experiments or studies on non-human species such as rats, frogs, etc., scientific research ethics outlines that individuals are expected to increase their understanding of the species under study before conducting experiments on them. By better understanding the physiology, characteristics and vulnerabilities of a species, we can design our experiment in a way that causes as little harm as possible to the species.  

Water(like when there is a hurricane)some foods(not enough for everyone)