Which of the following represents the measurement of 1 teaspoon in milliliters?

One teaspoon is commonly standardized to be equivalent to 5 milliliters (ml) in measurement. This conversion is a widely accepted measurement in both cooking and medicine, aiding in proper dosing and ingredient measurement. Understanding this conversion is crucial for individuals responsible for administering medications or preparing food, as accurate measurements can significantly impact outcomes.

The other choices do not reflect the commonly accepted volume of a teaspoon. For instance, 10 ml, 15 ml, and 20 ml exceed the actual measurement of a teaspoon, which could lead to incorrect dosing in medical situations or over or under-flavoring in culinary applications. Thus, recognizing that 1 teaspoon equals 5 ml is essential for accuracy in various contexts.