(3) Secret passages have often shaped important historic events. During the 1300s, a secret passage helped free an English king who was taken captive by his enemies. In the 1330s, Roger de Mortimer took young King Edward III of England captive in an attempt to take over the throne. After the king’s supporters learned of his kidnapping, they discovered a secret passage into Nottingham Castle. This passage allowed the supporters to slip past the guards and arrest Mortimer for his crime. Which is the topic sentence of paragraph 3?

A) "In the 1330s, Roger de Mortimer took young King Edward III of England captive in an attempt to take over the throne."

B) "After the king’s supporters learned of his kidnapping, they discovered a secret passage into Nottingham Castle."

C) "During the 1300s, a secret passage helped free an English king who was taken captive by his enemies." Eliminate

D) "This passage allowed the supporters to slip past the guards and arrest Mortimer for his crime."

A topic sentence must convey the idea of the whole paragraph. In that sense the paragraph here works on the idea of secret passages being historically significant in the important events that changed the course of history.

Thus either the first sentence of the paragraph or this sentence fit the description stated above. Out of all the options given this statement directly refers to the theme and thus is the topic sentence.