T Transfers a building ($90,000 market value, $40,000 basis) plus a $60,000 recourse debt on the building, to a general partnership in exchange for a 30% capital and profits interest valued at $30,000. U transfers $70,000 cash for the remaining capital and profits interest. What is U's basis in his TU partnership interest?

a. $0

b. $12,000

c. $70,000

d. $88,000

e. $112,000

A short explanation/calculation is appreciated.