A depleting source of energy is
Fossil fuels
The correct option is (d).
Explanation of the correct option:
Non-renewable source of energy:
Explanation of the incorrect options:
Option A:
Wind is a renewable source of energy.
Option B:
Sunlight is a renewable source of energy.
Option C:
Water is a renewable source of energy.
Final answer: A depleting source of energy is fossil fuels