john believe he was right, he was very______
about it.
Pompous
Hardheaded
Smug••
Assured
Correct me
Corrected sentence: "John believed he was right, he was very smug about it."
To correct the original sentence, the word "smug" should be used to describe John's attitude. "Smug" means having or showing excessive pride in oneself or one's achievements. In the context of the sentence, it suggests that John was confident and self-satisfied in his belief of being right.