I would personnaly just go for Gabriel's solution rather than trying to do a fancy workaround which may work now but in the future might get 'fixed' which would break your code.
Its seems your Type C is not an actual extension of Type B. Its more like they are 'siblings' !?.
Therefore logically speaking you should have a type BC which extends Type A containing all the common code. Then Type B and C are extensions of Type BC with unique implementations of the Manage() method.
Of course its easy to say this from where Im sitting... I dont have a deadline to hit.
Good luck
Its seems your Type C is not an actual extension of Type B. Its more like they are 'siblings' !?.
Therefore logically speaking you should have a type BC which extends Type A containing all the common code. Then Type B and C are extensions of Type BC with unique implementations of the Manage() method.
Of course its easy to say this from where Im sitting... I dont have a deadline to hit.
Good luck