TOEFL Listening: TPO-TOEFL阅读TPO - M5XJXR3L062WE0_5N$

Why does the author mention "toothpaste" being squeezed from a tube? A. To compare the movement of toothpaste from a tube to the movement of precipitation from clouds B. To suggest that the process of cloud formation is a simple, everyday experience C. To help the reader visualize the process of air movement over a city D. To contrast the slow rising of air currents with the rapid squeezing of toothpaste