The inductive effect is the permanent polarisation of sigma bonds caused by an electronegativity difference, transmitted through the chain with diminishing strength. A chlorine atom is electron-withdrawing and exerts a -I effect, pulling electron density away from the carboxyl group of the resulting chloroacetic acid. This stabilises the conjugate base, the carboxylate anion, by dispersing its negative charge, so the acid loses its proton more readily and acidity increases. The option that acidity decreases is wrong because only electron-donating (+I) groups would destabilise the anion and weaken the acid. The claim that acidity stays the same ignores the clear electronic perturbation introduced by chlorine. The idea that it becomes a base is incorrect since a carboxylic acid retains its acidic -COOH group regardless of substitution. This trend matches the NCERT ordering where chloroacetic acid is markedly stronger than acetic acid. Plausibility check: greater stabilisation of the negative conjugate base always corresponds to a stronger acid, consistent with increased acidity.