What is the purpose of the symbol that is encircled on this timeline?

A. It indicates that a period in history is lost or unknown.
B. It indicates that a break has happened in the even spacing of events.
C. It shows that a date occurs before year 1 on the Latin calendar.
D. It shows that a date occurs on or after year 1 on the Latin calendar.

What is the purpose of the symbol that is encircled on this timeline A It indicates that a period in history is lost or unknown B It indicates that a break has class=