Which of the following is a unit for measuring volume in the apothecary system?

• A. milliliter
• B. gallon
• C. liter
• D. fluid dram

Answer: (D)

Verified step by step guidance

1. Understand that the apothecary system is a historical system of weights and measures used in pharmacy, which includes specific units for volume such as the fluid dram, fluid ounce, pint, and gallon.
2. Recognize that the milliliter and liter are units from the metric system, not the apothecary system.
3. Identify that the gallon is a unit of volume but is primarily used in the US customary and British imperial systems, not specifically the apothecary system.
4. Recall that the fluid dram (also spelled fluidram) is a unit of volume in the apothecary system, commonly used to measure small liquid volumes in pharmacy.
5. Conclude that among the options given, the fluid dram is the correct unit for measuring volume in the apothecary system.