Gryffindors follow their gut and try to do good, no matter the cost. They are okay with putting their own life on the line, but their friends and loved ones can be their weakness. They want to be the hero and can get jealous of others or be worried about what might happen to them.
Ravenclaws will choose the smart option. They'll choose the option that benefits the most people, even if one person has to get the short end of the stick.
Slytherins choose the necessary option. They're okay with hurting someone's feelings when it has to be done. Slytherins set their eyes on a goal and will achieve that goal no matter what.
Hufflepuffs do what is kind. They believe strongly in justice, but they also believe in mercy. This often leads to conflict with themselves. They try to do the best for everyone- unlike Ravenclaw, they don't want to give anyone the short stick. Like Gryffindors, they're more selfless, but they're not always brave enough to throw themselves into the fight.
A Zombie apocalypse has occurred. You're on the run with an old woman, a child, and a grumpy man. You might be able to survive if you are able to run across the bridge before the zombies spot you.
Gryffindor/ Hufflepuff: Try to take everyone and do their best to make sure no one is left behind
Ravenclaw/Slytherin: Even though it's a hard decision, you need to leave the old woman behind. She has no hopes of running and you'll all die.