the total charge a battery can supply is rated in ma⋅h, the product of the current (in ma) and the time (in h) that the battery can provide this current. a battery rated at 1000 ma⋅hr can supply a current of 1000 ma for 1.0 h, 500 ma current for 2.0 h, and so on. a typical aa rechargeable battery has a voltage of 1.2 v and a rating of 1800 ma⋅h.

It depends on the subject for me. some exams are easier than others so i usually go through it and answer questions i know based on my general knowledge, then double check after. going through the lesson can a lot  because the exams can be  very lesson-specific, but sometimes they are ridiculously long so a lot of people don't take the time. i did find that, when i went through the lessons, i was making 100's on my exams vs strictly using + the internet and  i make 90's. 

The answer is a or b