Answer:
The correct answer is option d. "sunlight".
Explanation:
The sunlight is the major source of energy for organisms on Earth. Producers, such as plants and algae, use energy directly from the sunlight by the process known as photosynthesis. Other organisms such as consumers, eat organisms that get their energy from sunlight. Basically, all organism use sunlight as their fountain of energy or they obtain their energy from an organism that uses it.
