You can’t know the answer until you know the question. This might sound obvious, but many a point has been lost by the careless student who scans the answer choices hastily before properly understanding the question. Take the following example:

This is not a difficult question. The sodium will move by simple diffusion from a high concentration gradient to a low concentration gradient. But the question is long and contains a great deal of information, so that by the end, a hasty student might have mixed up whether there was a higher concentration of sodium inside or outside the cell. This sort of mix-up might happen to the hasty student on only a few questions, but a few questions are the difference between a 730 and a 680 on the SAT II Biology.

To avoid getting confused on any questions, take a moment to understand the question before answering it. Read the question, and then vocalize to yourself what the question is asking and what the pertinent information is. This process should not take more than a second or two. But those brief moments can make all the difference. For this question, once you’ve recognized what you’re dealing with, you will have little trouble in correctly answering C.