Read the sentence.

in class we learned about what triangles are and how to measure their angles the right way also.

which revision best corrects the faulty parallelism in the sentence?

a. in class we learned what triangles are and to measure their angles the right way.
b. in class we learned about what triangles are and also measuring their angles the right way.
c. in class we learned about triangles as well as learning about how to measure their angles the right way.
d. in class we learned about triangles and about the right way to measure their angles.