Means not personal; without reference or connection to a particular person; lacking human emotion or warmth.
a. conversation
b. impersonal
c. personal
d. interpersonal

Impersonal

Explanation:

We say something is impersonal when it does not refer to a specific person, but to people in general. Impersonality is a principle applied in law so that the public administration acts impartially before third parties, without benefiting or harming specific individuals, but always aiming at reaching the community or a broad group of citizens in an egalitarian way. This is a way of ensuring equal treatment for all citizens.

this question does't support enough resioning to answer.

well considering i can't see the graph, it's probably prices