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: t_1/2 = 5730 years), the age of the ancient artifact is

Correct option is C

Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon.
During its life, a plant or animal is in equilibrium with its surroundings by exchanging carbon either with the atmosphere or through its diet. It will, therefore, have the same proportion of ¹⁴C as the atmosphere, or in the case of marine animals or plants, with the ocean. Once it dies, it ceases to acquire ¹⁴C, but the ¹⁴C within its biological material at that time will continue to decay, and so the ratio of ¹⁴C to ¹²C in its remains will gradually decrease. Because ^​14C decays at a known rate, the proportion of radiocarbon can be used to determine how long it has been since a given sample stopped exchanging carbon – the older the sample, the less ¹⁴C will be left.