Mark is an ordained minister. Marks salary from his employing church last year was $31,000. The church did not designate any of his salary as housing allowance. Mark spent $10,000 to rent his home last year. How much of Marks salary must be included when figuring net income for self-employment tax?

A) $21,000

B) $31,000

C) $41,000

D) $51,000