I'm not going to set myself up for them to continue to reject solutions until they find one that they like.
Here is where I see the problem lies. You are giving them the solutions to accept or reject. That isn't how it is done in my neck of the woods. That wouldn't fly. That is the definition of a railroad. You have your story you want to tell and the players jsut get to ride along looking out the windows as you announce the sight on the left and right sides of the car, and they can choose to view those sight if they want to, but you close the windows on them so they cannot see anything else along the way unless it is a sight you have already decided they CAN look at.
The players should be giving YOU (the DM) the solution they wish to try, and you accept or reject it. That is what player choice is about.
I see it like this. Me and you both present our players with a room they enter from the North. That room contains at least a closed door to each the East and West.
When they are ready to leave the room, you present them with the options: Would you like to take the door to the East, or the one to the West.
I ask them where they wish to go leaving them room. I don't make them choose either of the doors, I allow them to go back the way they came from the North, or attempt breaking through the wall to the South.
I gave them the room, but you decided on top of giving them the room, which way they must exit it.
That is the railroad. You have taken control of the characters away from the players, in order to follow your linear path to resolution.
A DMs job is not an easy one, and if you cannot let players try to do what they want with their characters, it just makes you a certain type of DM that there are players out there who enjoy.
What it doesn't do is make it the only or correct way to do it for all other people. If your players enjoy riding your train down the tracks, then I am glad you all are having fun. But it isn't the only way the game is played.
I have played in and run games where you A and Not A exist, just like a good CYOA book. When the players are wanting that it is good fun. I have also played in games where the players are given control to make their own decisions based on what it is they want to achieve, without a set "one and only one way" to achieve something, and often times, they come up with good ways BEYOND the example method to handle a situation I present, that are just as good or better.
Which is why I ended my first post in this thread stating that is my view, and his/her players may like it.
Just because you and your players like the way you play and DM, doesn't make it less of a railroad.
Off the tracks, the DM presents an obstacle, the players present their method to solve it, and the DM decides if that method will work; and this continues until a solution is found for overcoming that obstacle.
On the tracks, the DM presents an obstacle, then presents accepted solutions that the players must "choose" from.