Wish I can help, but I don't take chemistry. :(
fly sry
Answer:
A
Explanation:
Same air has special carakteristik features
Answer:
Cost to supply enough vanillin is 
Explanation:
Threshold limit of vanillin in air is
per litre means there should be
of vanillin in 1L of air to detect aroma of vanillin.

So, 
So amount of vanillin should be present to detect = 
As cost of 50 g vanillin is
therefore cost of
vanillin = 
Cheeze is the most one i hope it helps