Correct Answer: Ordeal

Solution : The correct choice is the second option .

In the context of "experiences that are very unpleasant or difficult", the word that best captures this meaning is "ordeal", which refers to an experience marked by extreme difficulty, hardship, or pain.

The meanings of the other words are:

• Pitfall : This refers to a hidden or unsuspected danger or difficulty, often encountered in a situation or course of action.
• Strident : This word describes a loud, harsh, or grating sound.
• Knack : This word refers to a skill, ability, or talent that someone has naturally.

Therefore, the right answer is ordeal .