I am confused by this question.

Question

Biodegradable plastics may not break down readily in the sea because
a. Submergence in the water will protect them from sunlight
b. the water will keep the plastic cool
c. microorganisms will rapidly coat the plastic
d. a and b above
e. all of the above

My book states that some manufacturers make biodegradable plastic by adding light-absorbing molecules that break down the plastic after a few months' exposure to sunlight. There is no evidence that this will solve the problem at sea, for, even at the surface, the water keeps the plastic cool, and it becomes coated with a thin film of organisms that shade it from the light. It may be that only people educated to act in a responsible manner will be able to reduce the tide of plastics pollution rising around the world.
I am confused because I'm not sure if it is e or b. Please decifer. Thanks

im not 100% positive but I think it's e!