The main feature of Sichuan cuisine is spicy. China is known as salty in the north, sweet in the southeast and spicy in the west. Dry food is salty, hot and humid food is sweet, and humid food is spicy. I used to hear a saying that "the sun in Sichuan, the wind in Yunnan, and the rain in Sichuan is like winter." This sentence reflects that there is a lot of rain in Sichuan, and it is particularly cold when it rains, and the air humidity is high. People living in Sichuan always feel that it is cold from the inside of their bodies, and eating peppers is to drive away the cold and get rid of the humidity. This is because chili contains a substance called capsaicin. Eating chili can make people's heart beat faster, their pores widen, their skin capillaries expand and thicken, their blood speeds up, their sweat glands open, and they sweat all over, so that the cold and moisture on their bodies are driven out of their bodies and they will feel warm all over.

Therefore, choose: D.