Which of the following metric prefixes corresponds to a quantity of 1 (i.e., the base unit)?

• A. no prefix (base unit)
• B. centi-
• C. milli-
• D. kilo-

Answer: (A)

Verified step by step guidance

1. Understand that metric prefixes represent powers of ten that multiply the base unit. For example, 'kilo-' means 10^3 times the base unit, 'milli-' means 10^{-3} times the base unit, and 'centi-' means 10^{-2} times the base unit.
2. Recall that the base unit itself has no prefix and corresponds to a quantity of exactly 1 times the base unit, or mathematically, \$1 \times 10^{0}$.
3. Identify that 'kilo-' corresponds to \$10^{3}$ times the base unit, which is 1000 times the base unit.
4. Identify that 'milli-' corresponds to \$10^{-3}$ times the base unit, which is one-thousandth of the base unit.
5. Identify that 'centi-' corresponds to \$10^{-2}$ times the base unit, which is one-hundredth of the base unit. Therefore, the prefix that corresponds to a quantity of 1 (the base unit) is no prefix at all.