Answer
C.
Work Step by Step
Microarrays look at the expression of many genes at once (C.) to give an overall pattern. They do not work with multiple genomes at once, falsifying D., and they look at more than one gene, making A. untrue. B. is wrong since gene presence is examined by genomics, but microarrays are a tool for looking at gene expression, one step further along the flow of information from gene to protein.
