The italicized pronoun <em>himself </em>is used as a <u>reflexive pronoun</u>, that is its type. <span>A </span>reflexive pronoun<span> is normally used when the object of a sentence is the same as the subject: I hurt myself, for example. </span>
A) The urbanization of the United Stats quickened due to technology improvements.
-This whole paragraph is on the subject of how technology quickly urbanized the United States. All of the other answers are factors that caused this to happen.