The following parallel reactions can produce either the desired (D) or undesired (U) products: A+B D A+B U (rate constant is KD) (rate constant is ku) reaction rate: I'D = KDCACB reaction rate: ru = kUCACB Because these are homogeneous reactions, the only reactor choice is CSTR. The values of kD and ku are nearly the same. In order to enhance the selectivity of the desired product D, answer the following questions: a. Do you use one CSTR, or a series of CSTR reactors with the same total volume? Why? b. How do you introduce A and B into the reactor(s)? Why? c. Can you enhance the selectivity by varying the reactor temperature? Why?