Question

A calendar is a system of organizing time over extended periods. Although there are other calendars in use today, most of the world uses the Gregorian calendar, which follows the Christian system dates and events.

The standard Gregorian calendar has two eras, which are
B.C. and A.D.
D.C. and B.C.
A.D.D. and B.C.C.
A.C. and D.C.

Answer 1

B.C. AND A.D.

Answer 2

thx

Answer 3

np ("