What is a United States liquid unit equal to 16 fluid ounces?

The correct answer is a pint because in the U.S. measurement system, one pint is defined as exactly 16 fluid ounces. This means that if you have a measurement of 16 fluid ounces, it can be directly converted to one pint.

To understand the context of the other units: a quart consists of two pints, which means it would equal 32 fluid ounces; a gallon consists of four quarts, translating to 128 fluid ounces; and a cup is equal to 8 fluid ounces. Therefore, knowing the relationships between these units helps clarify why a pint is the appropriate answer for 16 fluid ounces.