Four terms have been given, out of which three are alike in some manner and one is different. Select the one that is different.

A. Metre (m) → Fundamental SI unit (measures length).

B. Kilogram (kg) → Fundamental SI unit (measures mass).

C. Second (s) → Fundamental SI unit (measures time).

D. Volume → Derived unit (measured in cubic meters or liters, not a fundamental SI unit).

Volume is the odd one out because it is a derived unit, while the others are fundamental SI units.

Thus, the correct option is (d) Volume.