Direction: Choose the appropriate idiom from the options below to fill in the blank in the sentence, making it grammatically and contextually correct.
The detectives were ____________________ when they suspected the polite librarian of the art heist; the cunning thief turned out to be an unexpected figure, the museum's security chief.
1
selling like hotcakes
2
rolling with the punches
3
barking up the wrong tree
4
beating around the bush
5
drawing a line in the sand