When ____ to danger and conflict, men tend to increase blood pressure, ____ nervous or anxious. [ ]

A. exposed; felt

B. exposed; feeling

C. exposing; feeling

D. exposing; felt

将一个基址寄存器的内容加上一个变址寄存器的内容形成操作数的有效地址，这种寻址称为【 】寻址方式。