Risa Exchanges an Office Building with a $600,000 Adjusted Basis

Risa exchanges an office building with a $600,000 adjusted basis for an apartment building with a $1,000,000 FMV and $200,000 of marketable securities. What is Risa's basis for the apartment building?

A) $400,000
B) $1,000,000
C) $800,000
D) $600,000