Resting every 8 hrs not overpowered?!?
Anyone who thinks that option A is not overpowered has never really played a wizard!
Think about his, firs of all, at 10th level, you can cast every stat buff spell in the morning and go into the dungeon with +2-4 to every stat, and you didn't even need to spend a feat!
Cast Rary's Mnumonic Enhancer for all 4+ level spell slot 3x per day! You'll never need a wand again, because you have every 1-3rd level spell you know memorized 2-3 times!
Cast Greater magic weapon on the whole party, rest and go into the dungeon fully loaded!
etc, etc.
Now, you CAN do all of these things ONCE per day if you go by rule B. But if you do this then the wizard has to devote his whole spell selection for the day to this trick (meaning he has no significant attack spells that day). If he does this, then he had better be doing it at a safe base camp.
With Rule A, a 9th+ level wizard can just cast a rope trick, rest in complete safety, power up, cast another rope trick, power up, etc, etc. as much as he wants!
This is super uber powerfull!