Us is correct answer. Us is a pronoun. Direct object is a word or group of words that is acted on by a subject.
For Example of direct objects: Monica hit the ball. Raul carried his books in a backpack.
Hope this helps, and Thank you.
Short Answer: A
A really super writer could get away with putting the thesis statement in the conclusion of a paragraph piece. But present day English Departments have become very rigid about where the thesis is.
It is always in the introduction. The idea is that you have to guide your reader to the arguments that follow in the paragraphs to come between the introduction and the conclusion.
Subject: "Each of the staff members"
Verb: "take a training course in the new software."
