Which is an example of commensalism in the tropical rainforest?

a. insects lay eggs in the sloth's waste.
b. sloths are food for other animals.
c. algae live in a sloth's fur, providing it with camouflage.
d. parasites feed on the sloth's body.

A. Insects lay eggs in the sloth's waste.

Commensalism is a biological interaction, in which two species lives in association, in this relationship one species gets the benefit and the other one receives neither harm nor benefit.  

The insects gets shelter in the fur of the sloth. It shows commensalism in the tropical rainforest. Instead of dropping feces (waste) directly from the tree top.  The slot come down to ground. They create a pit with their nails and discharge urine and feces. They discharge their waste weekly. Insects lay eggs on this waste. The development of insect larva takes place  in the discharged waste. The adult insects then fly up into the treetops. The insects utilize sloth body as shelter. Therefore, it is an example of commensalism where only one species is benefited that is insect species and sloth species is neither harmed nor benefited.