The β-activity of 0.9 g of carbon from the wood of a present-day tree is 0.25 Bq. If the activity of 0.9 g carbon isolated from the wood of an ancient artifact is 0.19 Bq under the same conditions (14C : t1/2 = 5730 years), the age of the ancient artifact is
1
4010 years
2
3000 years
3
2268 years
4
5573 years