If your pedantic, you'll love this title.

"How I Met My Husband" by Alice Munro

Discuss the effectiveness of the surprise ending. How does Carmichael differ from Chris Watters? Can it be argued that the surprise ending is also inevitable and appropriate?

First, something I'd like to address, is a little pet peeve o' mine. "Discuss the effectiveness of the surprise ending." is not a question. It is a misnomer to call this question a "question" when the first sentence is imperative. In addition, telling someone, rather abruptly and rudely mind you, to "discuss" as matter-of-factly as this textbook just did gets someone fired. Lucky for people in general, I'm not yet 30. So, it wants to discuss? Let's discuss! I think the surprise ending was effective in making the story be published in an AP Lit. book so whackjob professors can get just a little recognition by their peers and so their head inflates so that it no longer fits through doors. How about you? Oh wait, I can't discuss this because it's just ME! A discussion requires at least two people. If you want a discussion, please join me, otherwise, don't ever in your life ask me to "discuss" something, ESPECIALLY in a QUESTION because that's where actual QUESTIONS go.

Carmichael differs from Chris Watters in that he is not a perverted vagabond looking to corrupt girls much younger than him. It's the conservative husband who will love her that we've all been waiting for!

It can indeed be argued that the ending was inevitable and appropriate. It can also be argued that the moon is made of cheese and I am the Queen of Sheba. But if Edie did end up with crazy Chris, it wouldn't have been satisfying to the reader at all in that she ended up with a total creep who would probably rape her the second time 'round.