The common themes that Romantic period, the victorian age, and the modern era is a theme about revolution and democracy. In the romantic period, characters have a romance like story but the revolt still circles in the storyline, it is same with the victorian age and modern era where the fight for democracy is being the center of the story.
A, B, and D begin statements that can stand by themselves logically. C begins a statement that shows how the previous statement and itself are connected. As such, the answer is C(As a result).
D should be ur answer have a goed day