What unit of measurement is represented by the letter G?

The unit of measurement represented by the letter G is the gram, which is a metric unit of mass commonly used in many areas including science and medicine. One gram is defined as one one-thousandth of a kilogram and is a fundamental unit in the International System of Units (SI). The gram is particularly important in the medical field for measuring medication dosages and laboratory substances, ensuring accurate and safe administration of treatments.

Other options represent different units of measurement—gallon relates to fluid volume, grain is an older unit for mass typically used in measuring less than a gram, and gram per liter expresses concentration rather than mass alone. Thus, the gram is the clear and widely recognized standard for mass in various applications, including those in healthcare.