Question

Fan + Medal
Which sentence has a nonparallel structure?

Answer 1

They need to think further about the problem and to learn more about the context.
He suggests that they think further about the problem and learn more about the context.
She expects them to think further about the problem and learning more about the context.
I can only suggest thinking further about the problem and learning more about the context.

Answer 2

Any ideas ?

Answer 3

A?

Answer 4

Yes, if that is not wrong, I can only think of D being correct. Because B and C are pretty much the same.