Option 1: Cheese is not known for providing instant energy as it is a high-fat food and takes longer to digest and convert into usable energy.

Option 2: Glucose is the correct answer. Glucose is a type of sugar that the body can quickly convert into energy. It is easily absorbed into the bloodstream, making it an ideal source for providing instant energy to athletes during physical activity.

Option 3: Ghee, which is clarified butter, is a high-fat food and does not provide instant energy. It takes longer to digest and utilize as fuel.

Option 4: Vitamins are essential for maintaining overall health, but they do not provide instant energy. They play a role in various bodily functions but are not directly converted into energy.

In conclusion, out of the given options, glucose is the food that provides instant energy to athletes.