Answer: Option b Sunlight
Explanation:
- A limited resource is the one which is available in the least quantity in a given environment.
- The amount of sunlight is not available uniformly along the depth of the ocean. The uppermost layer of the ocean receives the most sunlight and is called the photic zone, whereas the lower depths of the ocean are called as the aphotic zone as they do not receive any sunlight at all.
Thus, in the lower depths sunlight is considered as the limited resource.