Answer:
D: Professor
Explanation:
If you look at the work academician, it is very similar to the word, academics, which means learning. So it can't be dentist. "cian" is found in mathemati<u>cian</u>, magi<u>cian,</u> musi<u>cian</u>...
The point is, it's related to a profession. If you break musician down, it breaks down into "music" and "cian". Musician is someone who has a profession in music.
So, if we break down academician, it makes "academic" and "cian". That means that this is someone who has a profession in teaching. That leaves us with professor.
Hope this helps!