A consecutive reaction, $A\stackrel{K_1}{\to }B\stackrel{K_2}{\to }C$, is characterised by :

The correct option is B maxima in the concentration of B
$A\stackrel{K_1}{\to }B\stackrel{K_2}{\to }C$ is characterised by maxima in the concentration of B. The maxima can occur for intermediate.
In the reaction, $A$ decreases in a single-exponential phase, $B$ increases exponentially, reaches some maximum value and then decays back to zero, and $C$ increases in a exponential manner.