Here's link to the answer:
tinyurl.com/wtjfavyw
Answer: i think there were two groups that wanted freedom so they came up with simillier names
Explanation:
A.D means in our time (Anno Domini, the year of our lord) and B.C means Before Christ - these two and the other mentioned words are used to B. refer to periods of time.
I believe True but I'm not 100% postive