If you understand it and learn it, then you wouldn't have to memorize it. Studying and memorizing doesn't always equal learning. Understanding lasts... memorizing fades away.
Multiple choice tests are the hardest, because they try to be tricky sometimes by giving you similar answers to choose from. You just have to go into it accepting that you may not get a perfect score.
Most college kids come to the understanding that the goal isn't to be perfect... it's basically just to pass and graduate. Once you graduate, most likely you will be competing with high school grads unless your field of study is specific.. ie. doctor, lawyer, engineer...
Supervisor, Manager, etc... any high school grad can achieve that same position and will most likely have a better shot at getting it... company won't have to dish out quite as much $$$ for that person to do the same job.
Anyway, I digress...
Read the question... understand what it's really asking. Look at ALL the answers instead of just picking the first one that seems to make sense. Realize that the whole purpose of a multiple choice test is to try to trick you into picking the wrong one. It forces you to really understand the subject because it takes away the possibility of the test-taker BS'ing his or her way through it.