Question

HELP NOW ASAP/

Answer 1

The answer is:

B) Frank studied for two M.A. degrees, and he earned a doctorate before he landed his current post as a math instructor.

Comas are used to make pauses and separate ideas, in this case the last one does not need to be separated because is easier to understand without the commas.

Answer 2

It would be B because you don't need a comma on the last one.