Which of the following is an apothecary unit of measurement?

• A. meter
• B. grain
• C. kilogram
• D. liter

Answer: (B)

Verified step by step guidance

1. Understand that apothecary units are a system of measurement historically used in pharmacy for weighing and measuring medicines.
2. Recall that apothecary units include units such as grain, scruple, dram, ounce, and pound, which are primarily used for mass or weight.
3. Recognize that meter and liter are metric units used for length and volume, respectively, and kilogram is a metric unit of mass, not part of the apothecary system.
4. Identify that 'grain' is a unit of mass in the apothecary system, commonly used to measure small quantities of substances.
5. Conclude that among the options given, 'grain' is the apothecary unit of measurement.