You have received an invitation to a business reception with an important client marked RSVP(Please Respond), you are tentatively scheduled to leave on a business trip that day. You should …（ ）
选项：

A:ignore the RSVP because you probably can’t attend.
B:call immediately and explain the problem, asking if you can RSVP later when your schedule is firm.
C:RSVP, so you will have it covered, then don’t go if your trip comes through.
D:RSVP, then call to cancel at the last minute if your trip comes through.