Which statement about the sense of smell in humans is most accurate?

Question

Quizplus · Accepted Answer

While humans have only about 5 million olfactory receptor cells (compared to dogs, for example, who have over 200 million), each cell contains a specific type of receptor molecule that is sensitive to a specific set of odorants. There are over 300 different types of these receptor molecules, which can combine in various ways to enable humans to detect and distinguish between thousands of different scents.

Which Statement About the Sense of Smell in Humans Is