The variation of decay rate of two radioactive samples $A$ and $B$ with time is shown in figure.
(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) Decays 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