Which one of the following statements is NOT correct?

In micelles, the orientation of soap molecules is opposite to what statement (d) describes. The hydrophobic (non-polar hydrocarbon tail) end faces inward toward the oil droplet/dirt, while the hydrophilic (ionic/polar) end faces outward toward water. This arrangement allows the soap to emulsify oily dirt and wash it away in water. Statements (a), (b), and (c) are all correct: soaps are indeed sodium/potassium salts of long-chain fatty acids, they have dual hydrophobic-hydrophilic character, and detergents work better in hard water because they do not form insoluble precipitates with Ca²⁺ and Mg²⁺ ions.