Cambridge Dictonary : Irony is a situation in which something which was intended to have a particular result has the opposite or a very different result
The answers are
D) The aunt wants the bachelor to learn his lesson, but she learns hers instead.
She didn't like the story he told the kids because it was not "appropiate" for kids and she tells him tha he has wasted years and years of good and careful teaching, refering to the way she has been teaching the kids but the irony is that even whith her methods of "good teaching" she couldn't entertain the children and the bachelor did it during 10 minutes in a row.
E) Bertha thinks that it is good to win medals for goodness, but the medals get her killed.
Bertha surely was very proud to have won her good behavior medals and wore them when she slipped into the bushes, however it did not matter how well she behaved, her medals collided with each other and let the wolf know where she was hiding. The irony is that by being a good girl it ended up being eaten by the wolf.