For Each Paragraph, Select the Number of the Topic Sentence

For each paragraph, select the number of the topic sentence. Identify the topic sentence of the paragraph below.
(1) Playing video games may give doctors an advantage in the operating room, helping them save lives. (2) A 2004 study at New York's Beth Israel Medical Center tested thirty-three doctors on video game tasks that measured their motor skills, reaction time, and hand-eye coordination. (3) These are the same skills that are essential to performing laparoscopic surgery, which involves using a joystick to maneuver a tiny video camera inserted into a patient's body. (4) Researchers found that doctors who used to play video games for more than three hours a week were 37 percent less likely than nongamers to make mistakes. (5) They also finished procedures 27 percent faster than nongamers.

A) Sentence 1
B) Sentence 2
C) Sentence 3