Physical quantities are identified uniquely by

The correct answer is units.

Step-by-step explanation:

A physical quantity must have a determined unit so it has a numerical value assigned to it. A unit is a standardized way to relegate a numerical amount to properties of a specific measurement. For instance, the meter (m), second (s), and kilogram (kg) are specific units that permit us to relegate numbers to estimations of length, time, and mass measurements.