Concept:Soap and detergent molecules have two different ends with opposite affinities for water.
Explanation:One end is the hydrophilic head, which is polar and strongly attracts water molecules.
The other end is the hydrophobic tail, a long non‑polar hydrocarbon chain that repels water.
This amphiphilic structure lets the molecule interact with both water and oily dirt.
The head dissolves in water, while the tail embeds into grease or oil.
Because of this arrangement, soap and detergent can lift and remove oily substances from surfaces.
The polar head is often an ionic group such as a carboxylate or sulfate.
The non‑polar tail is made of a long chain of carbon and hydrogen atoms.
Therefore, the general molecular architecture is always a hydrophilic head joined to a hydrophobic tail.
Answer:A. Hydrophilic head and hydrophobic tail.