The Trustee of the Dan Durrell Trust Is Authorized to Pay

The trustee of the Dan Durrell trust is authorized to pay to the wife $10,000 per year and at, his or her discretion, distribute income or corpus to the beneficiary. In 2012, the trustee has DNI of $20,000 and distributes $10,000 to the wife and $25,000 to the beneficiary. What is the beneficiary taxed on in 2012?

A) $15,000
B) $10,000
C) $20,000
D) $20,500