How do I calculate drift based on NDB readings?

An aircraft is to track from NDB A to NDB B. The RMI of NDB B reads 357 & RMI of NDB A reads 177. The aircraft is:

A: Drifted left of track
B: Drifted right of track
C: On track

I think it is 'C' but the answer is 'A' can someone explain this?

• Welcome to Aviation! Please edit your question to indicate why you think the answer is A so people can see where you've gone wrong and help correct your misconceptions. – FreeMan Jun 23 at 12:57
• @FreeMan, he thinks it is C and he is correct. The published answer A in whatever reference he took this from is not right. And if this is from an FAA test question database it wouldn’t be the first wrong “correct” answer... – Michael Hall Jun 23 at 17:04
• @MichaelHall thanks for your explanation and sorry for not being clear with the source. It's an answer that my friends noted. C is the right choice. – That guy who fly Jun 28 at 6:08