Which sentence provides the BEST supporting point to defend the author's position?

A) Teenagers should not be allowed to drive until they are 18.
B) Only high school graduates should be given a driver's license.
C) Some younger teenagers are perfectly mature and responsible, of course.
Eliminate
D) At 18, people are more mature and better able to make mature decisions.

D. At 18, people are more mature and better able to make mature decisions.

Explanation:

A supporting point is a detail of information that provides a proof or evidence of the writer's opinion or idea in a text. Such information should be relevant to the topic and should also be helpful in proving his side.

Among the choices above, letter D is the BEST supporting point to defend the author's position. For him, 18 is a better age for driving because the person is more mature. Thus, this is supports the idea on why teenagers should only be allowed to get a driver's license once they are 18 years old already.

So, this explains the answer.