How many milliliters are in 1 liter?

One liter is equivalent to 1,000 milliliters. This relationship is based on the metric system, where the prefix "milli" denotes a factor of one thousandth. Therefore, when converting liters to milliliters, you multiply the number of liters by 1,000. Since there is 1,000 milliliters in one liter, C is the correct answer. Understanding this conversion is crucial in pharmacy and healthcare settings, where precise measurements are vital for dosage calculations and medication administration.