The variation of decay rate of two radioactive samples A and B with time is shown in fig.

Which of the following statements are true?

Options

A. Decay constant of A is greater than that of B, hence A always decays faster than B.
B. Decay constant of B is greater than that of A but its decay rate is always smaller than that of A.
C. Decay constant of A is greater than that of B but it does not always decay faster than B.
D. Decay constant of B is smaller than that of A but still its decay rate becomes equal to that of A at a later instant.

Explanation

Rate of decay `(dN)/(dt) propto lambda`, so here `lambda_(A) gt lambda_(B)`. At the point of intersection of two curves, decay rate of both the samples is same. The correct options are (c) and (d).