Which process drives the formation of a bilayer when phospholipids are added to water?

Which process drives the formation of a bilayer when phospholipids are added to water?

a. Phospholipids self-assemble into a bilayer due to the strong affinity (attraction) they have for each other.

b. Hydrophobic forces cause water to repel the phosphate heads.

c. Phospholipids self-assemble into a bilayer due to their amphipathic (amphiphilic) nature.

d. Ionic bonds attract fatty acid tails to the interior of the bilayer.