The Sadistic Choice
One of the things that can make fiction compelling is an impossible, sadistic choice. Like in Hunger Games, when you want both Katniss and Peeta to live, but you know only one of them can. Or like I said about Open Minds, where Kira has to decide whether to lie about having no mind powers, to mindjack everyone she loves, or to tell the truth and put herself in serious danger.
An impossible choice keeps you reading, because you don't know what you would do in that situation, and you want to know what happens. BUT, there are some guidelines.
THE CHOICE HAS TO MATTER
Erasmo must decide whether to eat mango or papaya for breakfast. If he chooses the mango, the papaya will go bad, wasting his money. But he hates papaya. What will he do?
Compelling? Not so much.
THERE CAN BE NO EASY THIRD OPTION
Erasmo recognizes the cab driver as a convicted serial killer, but if he doesn't take the cab to work he'll be fired. What can he do?
How about call a different cab (and the police)? Nobody likes a dumb protagonist.
IT HAS TO BE A DIFFICULT CHOICE
Once at work, Erasmo's boss forces him to clean the bathrooms with a toothbrush or he's fired!
Neither option is pleasant, that's true, but it's not hard to figure out what he'll do.
DON'T DRAG IT OUT
Erasmo reads Hunger Games to see who Katniss will choose: Peeta or Gale. He waits. And waits. And waits...
Putting off a decision is valid and practical, but there should be either a reason ("We're at war! Now is not the time!") or consequences ("I didn't choose either and now they both hate me.").* Don't expect your compelling, sadistic choice to carry the reader through your story by itself.
* For the record, Hunger Games did both of these, but I still felt like Katniss was leading the guys on unnecessarily.
IT HAS TO BE RESOLVED
After everything he's been through, Erasmo takes the day off. He'll have to make the same decisions the next day, but I don't want to write about it.
I guess this could be a wacky literary ending, but I've never been a fan of those. If you do leave things unresolved, do so very, VERY intentionally (see Inception; seriously, go see it).
At this point, it's important to mention how the Sadistic Choice is usually resolved: with a previously unconsidered Third Option. It needs to be said, because it's easy to drop a Third Option out of nowhere and think you are, by default, being original. You're not.
As soon as you present the choice, your very intelligent readers will be looking at all the options, including the ones you haven't presented as possibilities. Especially the ones you haven't presented as possibilities. This makes it very hard to do something they don't see coming (which is, after all, the goal). How you do that is up to you.
Or else it's another blog post. I don't know. I haven't decided.