Select the word opposite in meaning to the underlined word.

How is one expected to deal with a persistent salesmen who won't take no for an answer?

Option 1 -> unscrupulous means lacking moral principles, which relates to ethics rather than consistency of behavior.

Option 2 -> tenacious means holding firmly to something; actually a synonym of persistent, not an antonym.

Option 3 -> vacillating means wavering or being indecisive; the opposite of being persistent or constant.

Option 4 -> determined means firmly decided; another synonym of persistent, not an antonym.

Hence, Option 3: vacillating -> A persistent salesman continues firmly without wavering, while a vacillating person wavers and is indecisive—these are opposite behaviors -> correct