One Day,20 People Show Up at a Baseball Diamond,13 Males

One day,20 people show up at a baseball diamond,13 males and 7 females.Since only 18 people are required to form two teams,two people are to be chosen at random to be the referees (umpires) .What is the probability that one of them is male and one is female?

A) 22.75%
B) 23.95%
C) 45.50%
D) 47.89%