What you wanna do here is use a calculator, as "e" in mathematics refers to the "e" on a calculator. The tricky part about this question is that the answer for the equation is the given percentage, NOT the value for "x". From there, plug in the multiple choice answers for "x" and see which one works!
In this case, A is the correct answer. B is absurdly large, so I omitted it immediately in the attached picture.
In this case, A is the correct answer. B is absurdly large, so I omitted it immediately in the attached picture.