Convert 4 teaspoons to milliliters. (1 teaspoon = 5 mL)

To convert teaspoons to milliliters, you can use the conversion factor given, where 1 teaspoon is equal to 5 milliliters. Therefore, to convert 4 teaspoons to milliliters, you would multiply the number of teaspoons (4) by the number of milliliters per teaspoon (5 mL).

Using this calculation:

4 teaspoons x 5 mL/teaspoon = 20 mL.

Thus, the correct conversion results in 20 milliliters. This method accurately reflects the relationship between teaspoons and milliliters based on the defined conversion factor and demonstrates the process of unit conversion effectively.