Old people are usually more conservative than young people.

Answer: Option B

Conservative : averse to change or innovation and holding traditional values.
Reproachful : expressing disapproval or disappointment.
Liberal : willing to respect or accept behaviour or opinions different from one's own; open to new ideas.
Dynamic : (of a process or system) characterized by constant change, activity, or progress.
Modern : relating to the present or recent times as opposed to the remote past.

Antonym of Conservative is Liberal