Which metric prefix indicates a factor of one, meaning no multiplication or scaling?

• A. no prefix
• B. kilo-
• C. centi-
• D. micro-

Answer: (A)

Verified step by step guidance

1. Understand that metric prefixes are used to indicate multiplication or division by powers of ten to scale units up or down.
2. Recognize that 'kilo-' means a factor of 10^3 (or 1000 times the base unit), 'centi-' means a factor of 10^-2 (or one hundredth of the base unit), and 'micro-' means a factor of 10^-6 (or one millionth of the base unit).
3. Identify that when there is no prefix, the unit is used as is, meaning it is multiplied by a factor of one (10^0), which means no scaling occurs.
4. Conclude that the metric prefix indicating a factor of one is actually the absence of any prefix.
5. Therefore, the correct answer is 'no prefix' because it represents the base unit without any multiplication or division.