Decoding the SI prefix "m" in mW for power units

Steps:

• Identify "mW" as a unit of power using the SI prefix "m" with watt (W).
• Recall that the prefix "milli-" (m) means 10^-3 in the International System of Units.
• Match this to the options: milliwatt is 10^-3 W, while others use different prefixes.
• Confirm C aligns with the definition of milli- as one-thousandth.

Why C is correct:

• The SI prefix "milli-" is defined as 10^-3, so mW equals one milliwatt or 0.001 watts.

Why the others are wrong:

• A: "Mega-" prefix means 10^6, so megawatt is MW, not mW.
• B: "Kilo-" prefix means 10^3, so kilowatt is kW, not mW.
• D: "Micro-" prefix means 10^-6, so microwatt is μW, not mW.

Final answer: C