The value of c is { c | c ∈ R, c ∉ {-1,0,2,12} }.
c is a number such that it is not in the set {-1,0,2,12} else we end up with a domain value having multiple range values, contradicting with the definition of a function.
I would don't really have the answer to this question maybe try rewording it
I believe the answer is D. 1.121, 1.21, 1.432, 1.53