An activity designed to introduce the metric system to fourth graders begins by asking students to use metric measurement to measure the length of their foot, their height, and the length of the classroom. It then asks them to use a thermometer and record the temperature of the classroom in degrees Celsius and to use a metric scale to weigh themselves in kilograms. Why is this activity a good way to introduce the metric system?

A. It is simple enough for fourth graders to do on their own or in small groups
B. The metric system is used worldwide and students must master the conversion between metric and U.S. customary units
C. This activity suits the interest in real-life experiences that young adolescents demonstrate
D. This activity allows students to practice measuring before they actually begin experiments