B, when cooking "Dragon Wonton Soup", the "white gas" constantly emerging in the pot is a liquefaction phenomenon, not a vaporization phenomenon, which is wrong;
C, when the water boils, continue to absorb heat, and the temperature remains unchanged. Therefore, when the water in the pot is boiled, the fire will be full and the water temperature will not rise, which is wrong;
D "Dragon Wonton" will smell bursts of fragrance when it is almost cooked, which is a diffusion phenomenon. It is correct to say that molecules keep doing random motion.
So choose ad.