Gerald Received a One-Third Capital and Profit (Loss)interest in XYZ

Gerald received a one-third capital and profit (loss) interest in XYZ Limited Partnership (LP) . In exchange for this interest, Gerald contributed a building with an FMV of $27,000. His adjusted basis in the building was $13,500. In addition, the building was encumbered with a $8,100 nonrecourse mortgage that XYZ LP assumed at the time the property was contributed. What is Gerald's outside basis immediately after his contribution?

A) $5,400
B) $8,100
C) $18,900
D) $21,600