The correct example of pronoun antecedent agreement is:
The dog wagged its tail.
In this sentence, "dog" (singular) is correctly matched with the pronoun "its" (also singular).
The other options demonstrate issues with agreement:
- "The cat chased their tail." (The cat is singular, but "their" is plural.)
- "The flowers bloomed in her garden." (Flowers is plural, but "her" is singular, which introduces some ambiguity.)
- "The birds flew away with his nest." (Birds is plural, but "his" is singular, which is not consistent.)
Thus, the first option is the clearest example of pronoun antecedent agreement.