Explanation

(b)
Group $\left( - {COO}^{-} \right)$ at one end and on other end, it has Na^{+} ions, thus cationic micelle is formed.
Sodium acetate forms cationic micelles above a certain concentration. In the molecule of detergents and soap, the negative ions aggregate to form a micelle of colloidal size. In polar medium (like water), the negative ion has a long hydrocarbon chain and a polar.