When taking an exam, some students quickly answer all the questions they know how to do. If they
go back and revise their answers, they start second guessing themselves and end up changing their
choice from the correct answer to an incorrect one. Other students work through the exam very
slowly - they think things very thoroughly, revise their answers several times, and carefully make
sure they have not missed anything. In a class where we have both these types of students together,
the correlation between the amount of time spent on an exam and their grade should be:

A. Positive and fairly strong
B. Negative and fairly strong
C. Fairly weak