Ted Wang writes:
What is the meaning of rewarding in the following sentence,"Which vocation do you think is more rewarding, the professor or the journalist"?
Here are the two meanings given for the adjective rewarding in Merriam-Webster's Learner's Dictionary:
1 : giving you a good feeling that you have done something valuable, important, etc.
2 : giving you money or profit
The first meaning is more common and is most likely the meaning intended in your sentence above ("Which vocation do you think is more rewarding....?"). The speaker is asking which vocation (=career) is more valuable and satisfying.
I hope this helps.
Jane