The correct answer is C. “Your father will buy you a new bag.”
The other options are incorrect because they do not follow the correct grammar rules.
Option A, “buy new bag for you,” is incorrect because it does not use the correct preposition. The preposition “for” is used to indicate that something is being done for someone else. In this case, the father is buying the bag for the child.
Option B, “buy you new bag,” is incorrect because it does not use the correct verb tense. The verb “to buy” takes the simple present tense when it is used to talk about a future event. In this case, the father is buying the bag in the future.
Option D, “No correction required,” is incorrect because the sentence does need to be corrected. The correct sentence is “Your father will buy you a new bag.”