C is the answer
got it now
Did you ever find out the answer for this?
Its definitely not D, took the test.
When proofreading sentences involving subject-verb agreement, it is important to note that the verb used should be suitable to the subject, whether it be in terms of number --- whether plural or singular --- and the person --- whether 1st, 2nd, or 3rd
C) an argumentative essay is based completely on fact.
