Why Do the Eras of the Pharnerozoic Eon All End

Multiple Choice

Why do the eras of the Pharnerozoic eon all end with "zoic"?

A) They are based on rock called zoisites.
B) These names refer to life or living things; they invoke the changes in fossil organisms from one era to the next.
C) "Zoic" means "time" in Latin.
D) These eras were all first described near the London Zoo, so the names pay tribute to that location.