Gavin Owns a 50% Interest in London Partnership Calculate Gavin's Tax Basis in His Partnership Interest at the Basis

Gavin owns a 50% interest in London Partnership. His tax basis in his partnership interest at the beginning of the year was $20,000. His partnership Schedule K-1 showed the following: $\begin{array}{llr} \text {ordinary buslness lncome } &\$60,000\\ \text { Share of partnership debt, beginning of year } &10,000\\ \text { Share of partnership debt, end of year} &15,000\end{array}$
Calculate Gavin's tax basis in his partnership interest at the end of the year?

A) $85,000
B) $95,000
C) $75,000
D) $65,000