GMAT Sentence Correction (SC) | Re: Many investors base their choice between bonds and stocks on

Let us not bother whether it is‘comparison with’ or‘comparison to’ , which I understand is not being tested by GMAT these days. But the primary clue is that a preposition such as‘on’ has to be followed by a noun or noun phrase. There is no escape from this rule. So it has to be‘on comparisons of ’. Any other expression may be ignored from consideration. So ADE are out. Between B and C, as the comparison is essentially between two things namely bonds and stocks,