The reason for wafting or fanning a small amount of chemical vapors toward the nose as a means to detect odors in a test tube is to: a. avoid experimental error from excessive loss of mass of reactants or products
b. avoid splashing chemicals into the face of any person
c. protect the respiratory tract against potentially harmful vapors
d. determine the relative strength of the odor before smelling directly

b is the correct answer

since you have not provided the options here i   am going to give you general overview about hormone.hormone are actually the part of endocrine system in our body and produced by the endocrine glands. the hormones act like a chemical messenger   within human body. once produce by the glands they   travel through the blood stream and reach at specific or target tissue and organs   which result in control of our body function. the hormones are specific in their work and work on only the targeted tissue or organ   . with the of hormone endocrine system regulate the heart rate , metabolism, our mood and   growth as well as the development and even the sleeping cycle etc. they actually are the messenger for body cell and organs .