Monroe contributed $20,000 of cash in exchange for a 50% interest in the Salmon partnership capital and profits. During the first year of partnership operations, Salmon had net taxable income of $50,000. Also, Monroe received a $15,000 distribution of cash from the partnership and he has a 50% share in the $15,000 of partnership recourse liabilities on the last day of the partnership year.What is Monroe's at-risk basis at year-end

a. $78,000.

b. $45,000.

c. $37,500.

d. $30,000.

e. None of the above