Which of these is NOT true about an allusion?

Responses

It can refer to something personal that is not known by most people
It can refer to something personal that is not known by most people

It can refer to a thing that is universally known
It can refer to a thing that is universally known

It can refer to a person that is universally known
It can refer to a person that is universally known

It can refer to a place that is universally known

It can refer to a place that is universally known