Which of the following is the base SI unit for mass?

• A. gram (g)
• B. kilogram (kg)
• C. pound (lb)
• D. milligram (mg)

Answer: (B)

Verified step by step guidance

1. Understand that the International System of Units (SI) defines standard units for various physical quantities, including mass.
2. Recall that the base SI unit for mass is the kilogram, symbolized as \(\text{kg}\), which is the only SI base unit with a prefix.
3. Recognize that the gram (\(\text{g}\)) and milligram (\(\text{mg}\)) are derived units based on the kilogram, where 1 kilogram equals 1000 grams and 1 gram equals 1000 milligrams.
4. Note that the pound (\(\text{lb}\)) is a unit of mass used primarily in the imperial system and is not part of the SI units.
5. Conclude that among the options given, the kilogram (\(\text{kg}\)) is the correct base SI unit for mass.