Mitosis
because the cell split into two identical copies!
What this student is doing is collecting data. So, he wants to check how many life forms there are in the waters nearby. In order to do so, he has to take a sample, and look at it through a microscope so as to determine the number. So, he collected a sample which is his data. He is not drawing conclusions yet, but rather counting these organisms. He is not making a peer review - his peers aren't even mentioned here. He is not forming a hypothesis because he is just counting at this point.
I think you forgot to give the options along with this question. I have researched with the question and have found the options as well. Hope it helps you in your study. Among the choices that i have come up with, the option that says that temperate deciduous forests are less open than tropical rain forests.