Select the most appropriate idiom that can substitute the highlighted words in the given sentence.
His sudden resignation left the company in a very difficult situation and to have to make a hard decision as they scrambled to find a replacement.

The correct answer is "(b) between a rock and a hard place."
· Explanation:
· "Between a rock and a hard place" means facing a difficult situation with no easy solution.
· Incorrect Choices:
· (a) on cloud nine – Incorrect, means "very happy."
· (c) in the dark – Incorrect, means "lacking information."
· (d) with a silver lining – Incorrect, means "finding something good in a bad situation."
Thus, the correct sentence is:
"His sudden resignation left the company between a rock and a hard place as they scrambled to find a replacement."