Find out whether there is any grammatical error in below sentence.
I could not convince them / because they persisted to suggest / that I was lying.
A. I could not convince them
B. because they persisted to suggest
C. that I was lying
D. No error
Answer: Option B

actually persisted is that action word which is self-satisfactory and complete has meaning in itself so it is unnecessary to use persisted to suggest or persisted in suggesting.