Correct Answer: A black sheep

Solution : The correct option is the fourth option.

Explanation:

A black sheep refers to a person who is seen as different or disgraceful compared to the rest of their family or group due to their behaviour or actions. It implies someone who stands out negatively among others.
The meanings of the other options are as follows:

• A fish out of water means someone uncomfortable or out of place in a particular situation or environment.
• A white elephant refers to something that is expensive to maintain or possesses no real value.
• A lone wolf describes someone who prefers to act independently or solitary, often avoiding the company of others.

Therefore, the correct answer is a black sheep.