Consider the following relations
x, y are real numbers and
for some rational numbers }
S = {
m, n, p and q are integers such that n, q ≠ 0 and qm = pn }
Then
a) R is an equivalence relation but S is not an equivalence relation
b) Neither R nor S is an equivalence relation
c) S is an equivalence relation but R is not an equivalence relation
d) R and S are both equivalence relations