Correct option is C
The correct answer is:
(c) to pay off a massive amount of
· "Pay up" is colloquial and not appropriate in this formal context. The correct expression is "pay off" when referring to repaying a debt.
· "Amount from debt" is incorrect; it should be "amount of debt."
Corrected sentence:
My financial advisor was helping me to pay off a massive amount of debt I incurred after medical school.