The control and experimental groups are designed to be identical true or false

False 

The control and experimental groups are not designed to be identical, since on one hand the experimental group gets a treatment (a medicine or something else). On the other hand, the control group does not get this treatment (or gets a 'fake' treatment). This way researchers can find differences between both groups and therefore can decide whether the treatment works or not.

Ithink that b is correct but just in case wait to see if someone else answers