The correct answer is D. The overwhelming number of geese at the park has become unacceptable.
Step-by-step explanation:
In a text, the point of view refers to an opinion or perspective a person has in reference to a situation or issue and the way this is conveyed through different elements. In the case of literary texts, the point of view is linked to the voice or narrator that tells the story, but in non-literary texts including letters, this point of view can be identified by analyzing the position of the author toward the events described.
In the excerpt presented the author states the purpose of the letter is to discuss a situation that occurred in the park, after this the author describes the situation itself that was that the author and his family decided to attend the annual picnic but were mobbed by geese. Finally, the author summarizes all the information and states "The overwhelming number of geese at the park has become unacceptable" which does not only cover all the points previously describe but clearly show the perspective or point of view of the author toward the situation described. Therefore, the sentence that contains the point of view is "The overwhelming number of geese at the park has become unacceptable".