posted by Dalton .
A Measurement is defined as_.
a. system of prefixes
b. the distance between two points
c. an exact quantity people agree to use for comparison
d. the interval between two events
c is fancy language, but it is almost correct, it is the best answer.
Measurement don't have to be exact, and usually are not...they have some precision, but nothing more than that. A pinch of salt is a measurement, but it is not exact.
an exact quantity people use for comparison