Let A={x:x is a prime factor of 240} and B={y:y is the sum of any two prime factors of 240}. Then which of the following options is true?
a and b are two positive integers such that the least prime factor of a is 3 and the least prime factor of b is 5. Then, the least prime factor of (a + b) is
(a) 2 (b) 3 (c) 5 (d) 8