Integration _______is the process of verifying that the components of a system work together as described in the program design and system design specifications．A．tryingB．checkingC．testingD．coding

A．(42，40，45，55，80，85)
B．(42，40，45，80，55，85)
C．(40，42，45，55，80，85)
D．(42，40，45，85，55，80)

A．2 ⁸
B．2 ¹⁰
C．2 ²
D．2 ¹⁸