JEE Main levelSingle correct optionDifficulty 2 of 3ev136
Assertion (A): Soft (biodegradable) detergents are preferred to hard detergents.
Reason (R): Soft detergents have unbranched hydrocarbon chains that bacteria can attack.
AA is false but R is true
BBoth A and R are true but R is not the correct explanation of A
CA is true but R is false
DBoth A and R are true and R is the correct explanation of A
Answer: D
Unbranched chains are degraded by bacteria, so soft detergents do not persist as foam in water. This is exactly why they are preferred, and R explains A.