The correct answer to the question is Unit i.e a measurement must include both a number and a unit.
EXPLANATION:
During the measurement of any physical quantity, unit plays a crucial role.
The magnitude of a measurement contains two parts known as numerical part and a unit.
This can be understood by an example.
If we say that a body is travelling 5, it gives no idea. Similarly, if we say that the box was pulled to distance metre, it has also no sense.
But, if we say that the body was pulled to 5 metre, it gives an idea about the distance travelled by the body in a specific time interval.
Hence, the magnitude of a measurement is written as -
m = nu.
Here, n is the numerical part and u is the unit.
