2. A chef pours a cup of rice into a pot of boiling water and observes the rice swirling around in the plot. Which of the following explains the cause of this motion? A. Heat transfer by radiation makes the rice vibrate.

B. The rice is carried along by conduction.

C. The chef stirred the pot before the rice was added.

D. The rice is carried along by convection currents.

Choose one correct answer.''