What type of work does the reeve perform?

a) He studies religious texts.

b) He orders goods for the university.

c) He is the superintendent of a farm.

d) He is a servant for members of the clergy.

The best answer here is C. If we refer back to the General Prologue from the start of The Canterbury Tales and read his description, we can see that he is described as a manager for someone's estate (as well as a carpenter, though that isn't necessary to know here). The majority of his description details his years of service to this particular farm and he is described as being quite good at what he does, able to predict crop yields.