BTU measures energy/heat content.

• A. Barrel of oil per hour
• B. Battery thermal unit
• C. British Tapered Unit; pipe threading
• D. British Thermal Unit; energy/heat content

Answer: (D)

BTU stands for British Thermal Unit, a unit of energy that measures the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit at standard pressure. This makes it a measure of energy content and heat transfer potential, which is why it’s used to describe the energy in fuels and the heating or cooling capacity of devices. The other options don’t fit: a barrel of oil per hour describes a flow rate, not energy; a battery thermal unit isn’t a recognized unit; and British Tapered Unit; pipe threading isn’t a real term related to measuring energy. So the correct choice captures energy/heat content.