Answer:
Diction.
Step-by-step explanation:
Diction is the use of certain words or the careful selection of words to be used, by a writer in his/her text. In other words, we can say that diction refers to the choice of specific words that a writer chooses to use.
This selection of particular words in speaking or writing helps the writer create a certain tone to the text. So, the use of specific words, the choice to accept one word and refuse the other, is what diction is all about.
Thus, the correct answer is the first option.