Why is a cork able to float on water?

Asmall in size
Ba solid
Cless dense than water
Dequal in density to water

Verified Answer :

CLess dense than water

I believe the answer would be C, less dense than water. 
The reason to why it floats because things like wood, cork, and ice tend to be less dense than water, hence they float. A rock, for example, is denser, so they sink. 

I hope this answers your question, good luck on your assignment.