If A={x:x is a prime factor of 30}A = \{x : x \text{ is a prime factor of } 30\}A={x:x is a prime factor of 30} and B={x:x is a prime factor of 42}B = \{x : x \text{ is a prime factor of } 42\}B={x:x is a prime factor of 42}, what is AΔBA \Delta BAΔB?
{2,3,5,7}\{2, 3, 5, 7\}{2,3,5,7}
{5,7}\{5, 7\}{5,7}
{2,3}\{2, 3\}{2,3}