Respuesta :
The answer is D because it's unclear who the pronoun in that sentence ("his") is referring to - is it Mario or Mario's little brother that it's talking about?
Answer:
The sentence that contains a vague pronoun is D: Mario gave his little brother a toy that he played with constantly.
Explanation:
This sentence contains a vague pronoun because after reading it we don't understand very well if the pronoun is referring to Mario or to Mario's little brother. Like it says at the beginning of the task, a vague pronoun is one whose reference is unclear, it leaves the reader wondering to whom the pronoun refers to.