Answer: (C)
Step-by-step explanation:
The text was based on Hitler's violations of the Treaty of Versailles, which confined Germany to a reduced military and a restrictive economic state. Through his idea of "lebensraum", Hitler began to break parts of the treaty to improve the state of Germany and reduce their impositions.
Because the text is centered around this message, only (C) makes sense as the central message of the text.
It's already established he was the Fuhrer, so not (A), and it expanded more about his invasions, so not (B). Nothing was mentioned about Italy, so not (D), so process of elimination is (C).