Per the Character builder. Anything in the current version, excluding playtest material is allowed. Anything not in the character builder is not allowed.
Note that the DM does not have every book and several player options need rules that are not contained within the Character Builder or online Compendium. It is the player’s responsibility to have a copy of any such rules available in hard copy form for the DM’s perusal. If such hard copy is not availabe, the DM may disallow or rule from the hip. Such ad-hoc rulings will not be retconned if later determined to be incorrect.