The correct answer is C.) Ability to deal with others, especially in difficult situations.
Explanation:
Having tact or being tactful refers to the quality of knowing how to communicate and interact with others appropriately, this means in every situation, and especially in difficult ones, you know how to act and what to say. For example, if you make inappropriate jokes or comments in a funeral this shows you are not being tactful because your language and actions are appropriate for the situation and instead they are offensive. Additionally, being tactful is one of the most important skills in interacting with others as this guarantees you keep good relations. Thus, the trait of being tactful can be described as "Ability to deal with others, especially in difficult situations".
A,C,B
First person is from the eyes of the narrator
Second person uses "you" to include the reader
Third person uses a narrator that is outside of the story or knows more than other characters
B, because nothing in this talks about dogs, and the main idea of the article is fish. It is more specifically about setting up a fish aquarium.