Answer:
a. pass readily through a membrane's lipid bilayer
Explanation:
Molecules or substances move to and fro the cell via the cell membrane, which is selectively permeable i.e. controls the passage of molecules in and out the cell.
Small, non-polar hydrophobic molecules such as fatty acids will not be repelled by lipid-containing cell membrane, hence, enters the cell via SIMPLE DIFFUSION. This means that they pass readily through a membrane's lipid bilayer without aid. Fatty acids are able to do this because they are a class of lipids and are soluble in lipid layer of the cell membrane.
