The largest energy store in a well-nourished adult isGroup of answer choicesLiver glycogenTriacylglycerol in adipose tissueBlood glucoseMuscle glycogen

The largest energy store in a well-nourished adult is Triacylglycerol in adipose tissue.

Here's a step-by-step explanation:

1. The human body stores energy in several forms for different purposes. These include glucose in the blood, glycogen in the liver and muscles, and triacylglycerol in adipose tissue.

2. Blood glucose and liver glycogen are quickly accessible sources of energy. They can be rapidly converted into energy when the body needs a quick boost.

3. Muscle glycogen is used primarily for muscle activities.

4. However, the largest energy store in the body is triacylglycerol stored in adipose tissue, also known as body fat.

5. Adipose tissue can store a much larger amount of energy compared to the other forms because fat is more energy-dense.

6. This energy is used when the body's immediate energy stores are depleted, such as during fasting or prolonged exercise.

So, the correct answer is "Triacylglycerol in adipose tissue".