Need Explanation for Answer!

[Shubh Dholakiya]

What would be It's answer guys because as per me it should be option A and as per IIT faculty answer is D. So please can anyone explain it's the reason that why D is the correct answer.

Let P be a subset of [(S×S)∖R]. What is the set of possible cardinalities of P?

A) {1,2,3,4,5,6,7,8,9,10,11,12}

B) {}

C) {1,2,3,4,5,6,7,8,9,10,11}

D) {0,1,2,3,4,5,6,7,8,9,10,11,12}