The Correct answer will be ON
Credible would be
Someone who's credible is honest and believable. ... Similar to words like reliable and plausible, credible is an adjective that comes to us from the Latin credibilis, meaning “worthy to be believed.” A credible reputation is often earned through consistent good behavior and an overall trustworthy personality.
Yes, scout dresses up as a ham in To Kill A Mockingbird for the school pageant.