Sun is essential for plants as it provides

The correct option is Energy.

Sunlight is the primary source of energy for almost all life on Earth, especially for plants. Plants contain a green pigment called chlorophyll, which absorbs light energy from the Sun.

Through a biological process called photosynthesis, plants convert this light energy into chemical energy. They use this energy to transform carbon dioxide from the air and water from the soil into glucose (food) and oxygen. Therefore, while the Sun helps plants produce food, what the Sun directly provides to the plants is energy.