Which of the following is the S.I unit of distance?
 

The SI unit of distance is meter (m). The meter is the fundamental unit of length in the International System of Units (SI), and it is used to measure distance or length in scientific contexts.

Explanation:

• The meter (m) is the standard unit of length in the SI system, while kilometers (km), millimeters (mm), and centimeters (cm) are derived units used for convenience but are not the base unit for distance measurement.