Answer: D (Kilogram)

**kil·o·gram** () The basic unit of mass in the metric system, equal to 1,000 grams (2.2 pounds). *See Table at* **measurement.** *See Note at* **weight.**

**metric system** A decimal system of weights and measures based on the meter as a unit of length, the kilogram as a unit of mass, and the liter as a unit of volume. *See Table at* **measurement.**