With no explanation, chose the best option from "A" or "B". Vanessa is good at math but her friend Sally is bad at math and if she fails the next math test she will have to repeat the grade. Vanessa wants Sally to pass the test.

A: Vanessa offers to let Sally copy off her during the math test.
B: Vanessa offers to help Sally study for the test and teach her what she doesn't know.
B.