请选择CBA1T5H/z/u0Z8c7X(TThe office building _____ the classrooms．4z7~7~0z9I4^0}-a9T'd'g+Q6m
A．behind4z7~7~0z9I4^0}-a9T'd'g+Q6m
B．behinds4z7~7~0z9I4^0}-a9T'd'g+Q6m
C．is behind4z7~7~0z9I4^0}-a9T'd'g+Q6m