R={(a,b):a=b−2,b>6}Now, since b>6,(2,4)∈/RAlso, as 3=8−2,(3,8)∈/RAnd, as 8=7−2∴(8,7)∈/R Now, consider (6,8).We have 8>6 and also, 6=8−2∴(6,8)∈R The correct answer is C.