Over the Years, Monica Contributed $15,000 to a Roth IRA

Over the years, Monica contributed $15,000 to a Roth IRA opened 10 years ago. The IRA has a current value of $37,500. She is 54 years old and takes a distribution of $25,000. How much of the distribution will be taxable to Monica?

A) $0
B) $10,000
C) $15,000
D) $25,000
E) $37,500