C. Many chemical are dangerous is the correct answer
Explanation:
It is important to waft when smelling chemicals because Many chemical are dangerous.
wafting chemicals is very important because chemicals are very dangerous they can cause damage to the mucous membrane and throat.
While working in the laboratory if we use a direct sniff of a chemicals the smell of the chemicals causes nausea and also a headache its odor can be very toxic that can harm human health.
Thus this is the reason wafting is important when smelling chemicals.
