Event Card Rulings

I have a question regarding what happens with event cards that say Destroy/Remove/Push X in/from a land with Y. If there are multiple lands with Y some of which contain X, must you choose a land with X. Additionally if there are multiple lands with both X and Y but there is an active effect in one of them that will prevent X from being Destroyed/Removed/Pushed, must you target the land without that effect?

For example let's say I'm playing Stone's Unyielding Defiance, I have played Stubburn Solidarity on a land with both beasts and dehan. There is another land with beasts and dehan. And a third land with only beasts. I am resolving the Overconfidence event card and am at the point where I destroy 1 (dehan) in a land with (beast). Can I

  1. Choose to destroy 1 dehan from any of those lands, including the one without dehan I just needed to choose to target a land with beasts. (even though this will have no effect in two of those lands)
  2. Choose between the two lands with dehan even though the ones in the land where I played Stubburn Solidarity will not actually be destroyed
  3. I have to destroy the dehan in the land that is unprotected 

> If there are multiple lands with Y some of which contain X, must you choose a land with X. Yes, you must do the effect if you can.

> Additionally if there are multiple lands with both X and Y but there is an active effect in one of them that will prevent X from being Destroyed/Removed/Pushed, must you target the land without that effect? You are free to choose the land where the effect will be prevented.

So in your question, option 2 is the correct answer.

(I know this has been discussed extensively, but I'm not sure where the canonical reference is right now.)