a, C 1 = {1;4};
b, C 2 = {1;5}; C 3 = {2;4}; C 4 = {2;5}; C 5 = {3;4}; C 6 = {3;5}
c, D 1 = {1;2;4}; D 2 = {1;2;5}; D 3 = {1;3;4}; D 4 = {1;3;5}; D 5 = {2;3;4}; D 6 = {2;3;5}
a, C 1 = {1;4};
b, C 2 = {1;5}; C 3 = {2;4}; C 4 = {2;5}; C 5 = {3;4}; C 6 = {3;5}
c, D 1 = {1;2;4}; D 2 = {1;2;5}; D 3 = {1;3;4}; D 4 = {1;3;5}; D 5 = {2;3;4}; D 6 = {2;3;5}