Mod·al verbnounGRAMMARplural noun: modal verbsan auxiliary verb that expresses necessity or possibility. English modal verbs include must, shall, will, should, would, can, could, may, and might.
Is this a trick question?
In expository writing, a topic sentence is a sentence that summarizes the main idea of a paragraph. It is usually the first sentence in a paragraph. What is your question regarding a topic statement?
The answer is D: After some soul-searching and introspection, Peter knew that it was time for him to move on.
Introspection is the action of self-reflection, that is to say, internal observation of one´s own state of mind. This kind of intra-personal observation can yield insights about one´s own corporeal, sensitive, cognitive and emotional states. It is contrasted to external observation of objects as different and external to the mind.