Best Answer Explained in Below-:

The phrase "in deep water" is an idiomatic expression used to describe a situation where a person finds themselves in trouble or in a difficult predicament. The origin of this expression likely stems from the idea of being in water that is too deep to swim in, which inherently conveys a sense of danger and vulnerability. When someone is in deep water, they may feel overwhelmed, unable to see a way out of the situation, or at risk of sinking, both figuratively and literally.

In contrast, the other options do not align with the meaning of the phrase. "Profound" (option A) suggests depth of thought or insight, which does not connect to being in difficulty. "Busy" (option B) implies being occupied or engaged in tasks, while "confused" (option D) refers to a lack of understanding or clarity, which is not directly related to being in a troublesome situation.

Thus, the core essence of the phrase aligns closely with option C, indicating that when someone is in "deep water," they are indeed "in trouble."