Reasoning time:
(A) I tested this on PS! already, and Disable goes through, making the Sky Attack user fail to act.
(B)
http://www.smogon.com/dp/articles/move_restrictions#disable and
http://www.smogon.com/dp/articles/move_restrictions#charge
Disable: When a Pokémon uses the move Disable, it locks the last move
executed by the target. This lock prevents both the
selection and execution of the move and remains in effect for 4-7 rounds or until the target leaves the field. If the last action taken by the target was not an executed move, Disable fails. If the targeted move has no PP left, Disable fails. Only one move can be Disabled per Pokémon at any given time.
Charge Moves: Charge moves are two-round attacks. The user charges the move on the first turn (the Charge Action) and delivers the attack on the second turn (the Attack Action). For the purposes of move restriction, the move is
selected once and executes twice. Both the
Charge Action and the Attack Action are considered an execution of the move. However, only one PP is used up each time the move is used. The PP is lost when the Charge Action executes.
Because the move is only selected once (before the Charge Action), preventing the selection of the move after the execution of the Charge Action will not prevent the execution of the Attack Action. The Attack Action bypasses the selection process entirely. However, preventing the execution of the move will prevent the Attack Action.
The Charge Phase of a Charge Attack is counted as an execution of the move, allowing Disable to target it. Since Disable blocks move selection and execution, the mon that was Disabled would then forfeit the turn because the restrictive effect was applied in the same round as it tried to act.