In each of the given questions, three sentences are given with a phrase/idiom highlighted in bold. You have to select the answer choice that states the combination of statements in which the idiom has been correctly used.

I. Shortly after announcing his candidacy, he received an anonymous poison-pen letter attacking his platform.

II. I accidentally called John by his brother's name. It was just a slip of the leg.

III. The critic must have dipped his pen in gall before writing that very negative review.