Suppose we have a set A={a,b,c,d}A = \{a, b, c, d\}A={a,b,c,d}. If A∪B={a,b,c,d,e}A \cup B = \{a, b, c, d, e\}A∪B={a,b,c,d,e} and A∩B={c,d}A \cap B = \{c, d\}A∩B={c,d}, which of the following must be the set BBB?
{c,d,e}\{c, d, e\}{c,d,e}
{e}\{e\}{e}
{a,b,e}\{a, b, e\}{a,b,e}
{c,d}\{c, d\}{c,d}