"Caught between two stools" means being in a situation where you are forced to choose between two options, but both are difficult or unappealing.
- "Met with an accident" refers to being involved in a mishap, which is unrelated to the idiom.
- "Difficulty in choosing between two alternatives" is the correct meaning of the idiom.
- "Struck in a calamity" and "doing two things at a time" do not match the meaning of this idiom.
When caught between two stools, you face a dilemma where neither option seems ideal.