Concept:Rule by old people is called gerontocracy.
Explanation:The word "gerontocracy" comes from Greek roots.
"Geron" means old man, and "kratos" means rule or power.
So gerontocracy literally means rule by the eldest or aged members of society.
In such a system, a council of elders or senior citizens holds political authority.
Monarchy is rule by a single king or queen, not by old people.
Feudalism is a medieval social system based on land ownership and loyalty.
Theocracy is rule by religious leaders or divine authority.
Only gerontocracy directly matches government by old people.
Therefore, the correct option is B.
Answer:B. Gerontocracy