The answer B.Since,Diffusion is driven by differences in concentration. When chemical substances such as perfume are let loose in a room, their particles mix with the particles of air. ... Diffusion in gases is quick because the particles in a gas move quickly. It happens even faster in hot gases because the particles of gas move faster.
False, the author just has to put enough details and opinions in the text, the the audience can feel what the author feels. That is called authors purpose.