We know that x is prime and it is greater than 2. So x is odd as two is the only even prime. Now is 3 * odd * y - even ? INSUFF without knowing the value of y.If x is a prime number, is 3xy even?
1). x>2
We know that x is a prime number and y is odd. is 3 * odd * x - even ? If x is two then even else odd. INSUFF.2). y is odd
Combining both we get x is odd and y is odd as well and 3 is odd. So the 3xy is odd. Hence SUFF.
IMO C.
