In the sentence "We must help the victims in the earthquake out of trouble ", the underlined part is an additional explanation of

A．he has known her address.
B．he knew her address.
C．he didn’t know her address.
D．he asked for her address.

A．The test questions are kept secret so as to prevent cheating.
B．In order to prevent cheating, the test questions are kept secret.
C．They started early in order to get there in time.
D．So as to get there in time, they started early.