Question

read the paragraph. then, add the best topic sentence.
_______ morgan came up with the idea to make a better traffic signal after seeing a bad accident. traffic signals used to switch between \stop\ and \go\ positions without any warning time in between. morgans new traffic signal added a third position to let people know when the signal was about to change. this gave people time to finish driving or walking across the street before traffic came the other way.
garrett morgan invented things to keep people safe.
in 1912, garrett morgan invented a safety mask for firefighters.
in 1923, garrett morgan designed a safer traffic signal.
garrett morgan was a successful businessman.

Explanation:

The paragraph focuses entirely on Garrett Morgan's creation of an improved, safer traffic signal. The correct topic sentence must directly introduce this specific invention. The first option is too broad, the second is about an unrelated invention, and the fourth is irrelevant to the content about the traffic signal. The third option specifically references the 1923 safer traffic signal design, which matches the details in the paragraph.

Answer:

In 1923, Garrett Morgan designed a safer traffic signal.