The metric system is based on the SI unit, which is the primary unit of length. What is this unit?

• A. centimeter
• B. inch
• C. meter
• D. kilometer

Answer: (C)

Verified step by step guidance

1. Understand that the metric system is a decimal-based system of measurement used internationally in science and everyday life.
2. Recall that the International System of Units (SI) defines base units for fundamental quantities such as length, mass, and time.
3. Identify that the primary SI unit for length is the unit from which other length units like centimeters and kilometers are derived.
4. Recognize that the meter is the SI base unit for length, and other units like centimeter and kilometer are multiples or submultiples of the meter.
5. Conclude that among the options given, the correct SI base unit of length is the meter.