11. For the multicast algorithm based on propagation trees, answer the following.

(a) About a tight upper bound on the number of multicast groups.

(b) About a tight upper bound on the number of meta-groups of the multicast groups.

(c) Examine and justify in detail, the impact (to the propagation tree) of (i) an existing process departing from one of the multiple groups of which it is a member. (ii) an existing process joining another group. (iii) the formation of a new group containing new processes. (iv) the formation of a new group containing processes that are already part of various other groups.