Answer: The olfactory nerve is the first cranial nerve which conveys the sensory information related to the smell.
The receptors are nasal mucosa and forebrain. The test to access the function of olfactory nerve has to be performed at a place which is free from any type of smell.
It should be clean and free from any type of smell. In this case the person is taken to a place which is clean and dry.
He is told that the test is being performed on him. He is being exposed to different smells such as vanilla, lemon which is not that strong.
Then person has to recognize the smell of different flavors if he is able to recognize the smell correctly then his olfactory is working correctly.