Correct option is B
The correct answer is (b) Metre.
Metre (m) is the SI unit of length, a fundamental physical quantity that measures distance or displacement.
It represents the dimension [L], and is used universally for expressing all linear measurements.
Information Booster:
SI Base Unit of Length: Metre (m)
Other Derived Units of Length: Kilometer (km), centimeter (cm), millimeter (mm), nanometer (nm)
1 metre: Defined as the distance traveled by light in vacuum in 1/299,792,458 seconds.
Length is a scalar quantity, having magnitude but no direction.
Additional Information (Why Other Options Are Incorrect):
(A) Joule: Unit of energy or work, dimensionally [ML²T⁻²].
(C) Ampere: Unit of electric current, dimensionally [I].
(D) Kilogram: Unit of mass, dimensionally [M].