Which of the following is NOT a metric unit of fluid measurement?

The choice of pint as the correct answer is based on the fact that it is a unit of measurement that belongs to the imperial system, primarily used in the United States and the United Kingdom, rather than the metric system. In contrast, milliliters, deciliters, and liters are all metric units established by the International System of Units (SI).

Milliliters are commonly used for very small volumes, deciliters are often used for measuring liquids in slightly larger quantities, and liters represent a standard measure for larger volumes of liquid. The metric system is based on powers of ten, which provides a universally accepted method for measuring and converting between units. This simplicity is one of the reasons why metric units are preferred in scientific and medical contexts.

Therefore, pint stands out as the only unit listed that is not part of the metric system.