As per the Legal Metrology Act, weights and measures, the base unit for mass is:

Correct option is B

The Legal Metrology Act, 2009 in India adopts the International System of Units (SI units) for standard weights and measures.
In SI units:
The base unit of mass is the kilogram (kg).
The mole is the base unit for measuring the amount of substance.
The pound is a non-metric unit (imperial system), not recognized under SI.
The kelvin is the SI base unit for temperature.
Therefore, the correct SI base unit of mass under the Act is the kilogram.
Correct answer → Option (b) – Kilogram.