While I am training for my TOEFL exam using an Android mobile application, I found this question which seemed trivial to me but it turned out to be more complicated. Can somebody help me understand the grammar behind this answer because all what I could find using Google is what I already know:
Before a person may drive a car on a public highway, it is necessary that he _____ a driving test.
- take (the right answer)
- is taking
- took
- takes (my answer)