A fractured cribriform plate (anterior skull trauma) can result in leaking of cerebrospinal fluid into the nose and loss of sense of smell. Smell plays a large role in the perception of taste. So, in practice, a patient may complain of loss of taste rather than of smell.
loss of olfactory you cant tell you eating apple or potato
It can't be the Facial nerve, physical examination was normal. Someone would probably notice the face symptoms.
I went with Glossopharyngeal, but that wasn't it.