If $P ( A \cup B ) = 1$ And $P ( A \cap B ) = 0$

Multiple Choice

If $P ( A \cup B ) = 1$ and $P ( A \cap B ) = 0$ , then which statement is true?

A) $A$ and $B$ are reciprocal events.
B) $A$ and $B$ are supplementary events.
C) $A$ and $B$ are both empty events.
D) $A$ and $B$ are complementary events.