单片机通过系统总线外接存储器时，P2可作为_______。 A.
8位数据总线 B.
低8位地址总线 C.
高8位地址总线 D.
16位数据总线

A．Only include factors that are considered very important.
B．Only include normative expressions.
C．Including all known factors related to reality.
D．Does not include the use of "other conditions are the same".