A liquid phase reaction is to be carried out under isothermal conditions. The reaction rate as a function of conversion has been determined experimentally and is shown in the figure given below. What choice of reactor or combination of reactors will require the minimum overall reactor volume, if a conversion of 0.9 is desired ?
A. CSTR followed by a PFR
B. PFR followed by a CSTR
C. CSTR followed by a PFR followed by a CSTR
D. PFR followed by a CSTR followed by a PFR