Which sentence best demonstrates grammaring?

• A. She work project 3 month
• B. She'll be working on the project for 3 months.
• C. They goes to the library.
• D. We has finished the assignment.

Answer: (B)

The main idea here is choosing a sentence that shows correct tense, agreement, and phrasing for a future ongoing action. This sentence uses the future continuous form: will be working, with the subject correctly paired as She, and the contraction She’ll stands for She will. This structure signals an action that will be in progress over a period of time, which is reinforced by the duration phrase for 3 months and the correct preposition on the project. The other options break grammar in different ways: one omits the auxiliary and proper preposition, another mismatches subject and verb form, and the last combines a plural subject with a singular auxiliary. So the sentence with future continuous tense and proper agreement and prepositional use best demonstrates grammaring here.