Having a huge archive of information in one's head implies that this person seeks knowledge in the world, and I would consider that one who seeks such knowledge, a "smart" person. I feel like this is because he/she is eager to learn/know more about the world. Perhaps "knowledgeable" is a better word for that kind of person.
Quick and effective problem-solving skills implies that the person thoroughly understands the problem (first step of problem-solving, after all) and can devise a method of going about the problem without any ease. If I can throw math problems at them and they're just spitting correct answers out, I would consider them "smart" as well.
Efficient comprehension and learning ability: I feel this somewhat relates to the above. If some one really understands the problem, he/she should be able to effectively solve it. However, efficient comprehension may also relate to such things like reading and writing skills. Like, for example, if someone understood the underlying meaning of many books. However, comprehension and learning ability may not be the best indication of intelligence either. Remember that Einstein had a learning disability; he did not make very good grades and his teachers thought he was retarded. He could not read until he was 9.
Memorizing large amounts of information with ease...Well, they say memorization is on the lowest level of the pyramid learning, so I'm not quite sure how I feel about this one. It's obviously no easy task to memorize large amounts of information, and the brain capacity it takes for it may/may not indicate intelligence. A lot of what we're taught in life often needs to be memorized. But memorization is nothing without comprehension of the material. One can recite the entire Constitution, but without knowing what it means, it's rather useless. However, I don't doubt that having great memorization skills doesn't hurt when it comes to being "smart". After all, aren't our every day processes and facts just built from memorization?
I'm actually torn between all four choices. I'm not quite sure if I can put an emphasis on any of them.
I would submit that with quick and effective problem-solving skills, ones learning ability depends only on how to look at the material as a problem to be solved. For comprehension... well, you cant solve a problem unless you comprehend it, right? And what good is memorizing and having a large store of information if you have no ability to apply it to the problem at hand?
True geniuses are amazing problem solvers. That is why I.Q. tests are heavy on problem solving questions.