The correct answer is: C) Heather wants to go to the store with us.
An infinitive is a verbal that can work as 3 different things: as a noun, as an adjective, or as an adverb. It is produced when using "to" + the verb, but this verb can't end in -ed, -ing or similar.
In this case, "to go" is the infinitive.
D) Recruiter.
On top of that, "experience in recruiting" basically gives it away. <span />
Perhaps direct a question to Ellen on whether she’s read any other book by the Author to justify why she hates the author