Q.19 att = 0, ng number of a radioactive nuclei a start decaying into b with a decay constant aa. the daughter nuclei b decay into nuclei c with a decay constan

Q.19 Att = 0, Ng number of a radioactive nuclei A start decaying into B with a decay constant Aa. The daughter nuclei B decay into nuclei C with a decay constant Ap. Then, the number of nuclei B at small time t (to the leading order) is (A) AaNot (B) (Aa-2»)Ngt (C) Aa+ 2»)Not (D) 2, Ngt 02