Which option best revises this sentence so that it uses parallel structure?

High school students should be required to do community service in order to graduate because it helps them build social awareness and helps them take a greater interest in their communities, as well as gaining necessary job skills.

A. High school students should be required to do community service in order to graduate because it helps them to build social awareness, taking a greater interest in their communities, and to gain necessary job skills.
B. High school students should be required to do community service in order to graduate because it helps them by building social awareness and to take a greater interest in their communities, as well as gain necessary job skills.
C. High school students should be required to do community service in order to graduate because it helps them build social awareness, take a greater interest in their communities, and gain necessary job skills.
D. High school students should be required to do community service in order to graduate because it helps them by building social awareness, taking a greater interest in their communities, and lets them gain necessary job skills.