week 15

Considering the PQR tree below, which of the alternatives contains sets that do NOT belong to the tree's complete collection?

a) { M N } and { M O }
b) { C D } and{ K L }
c) { A B }, { J K } and { L M }
d) { E F G }, { G H } and { H I }
e) None of the above.

Original idea by: Daniel M. Ivasse
Translation Help by: Mario Akita