I chose "other." I've found the relationships with them to be the hardest.. Us learning how to understand them, and living harmoniously with young kids.
Tikki our cockatiel is 99% kind except at bedtime. It's a struggle to keep him off the floor so he doesn't get stepped on.
Tootie our Nanday Conure is afraid of all touches, and has only stepped up once. He alarm calls if our toddler brings an item of any sort into the room and he doesn't recognize it. Not really an issue though, he is our almost perfect birdie and lives almost cage less because he is so darn good.
Chipper our Umbrella Cockatoo is still very new, only been here for not even a month, so he's still very hard. He's hard to read, hard to know what he likes /dislikes, and he's afraid of the children. We have lots of work to put in towards learning his ins and outs, and knowing that we'll probably get bit in the process is intimidating at times. But we're in it for the long haul.
It's easy to get a bird, throw it some toys and pellets and walk away, but establishing and maintaining a working relationship that everyone can enjoy most of the time is very hard!