Final answer:
The term that best describes carefully revising word choices in writing is diction.
Step-by-step explanation:
The term that best describes the concept of carefully revising word choices in writing is diction. Diction refers to the specific words and phrases chosen by a writer. In this context, the professor is suggesting that Tobin should pay attention to the subtle differences in word choice, as they can have a significant impact on the reader's interpretation and understanding of the paper.