In a radioactive sample K nuclei either decay into stable Ca nuclei with decay constant 4.5 x 10-10 per year or into stable Ar nuclei with decay constant 0.510-10 per year. Given that in this sample all the stable Ca and Ar nuclei are produced by the K nuclei only. In time t x 10 years, if the ratio of the sum of stable Ca and Ar nuclei to the radioactive 4K nuclei is 99, the value of t will be 18 [Given: In 10 = 2.3] A. 1.15 C. 9.2 B. 4.6 D. 2.3