Player A would not be able to the reveal since for each event players are only asked once.
This reasoning could be misconstrued as saying Player A doesn't get another opportunity to reveal enchantments, which is inaccurate.
If both players want to reveal an enchantment at the same time, the player with the initiative goes first. He may reveal as many enchantments as he wants, one at a time, resolving each one before revealing the next. When he is finished, then the other player may reveal any enchantments, revealing and resolving them one at a time. Then the first player can reveal again, and so on. Each enchantment is resolved as soon as it is revealed.
Thus, after Player B has revealed Rise Again, Player A can not reveal a Rise Again because the creature already has one on it, not because he doesn't get another chance to reveal.
I would also make clear that the reveal has to occur before the destruction event resolves rather than being able to do it in response to a destruction event. Usually, this would be between steps 3 and 4 of an attack as the latest you could reveal it. It might also be possible for a spell to destroy a creature without an attack though, in which case it must be revealed between steps 2 and 3 of casting that spell. For example, if someone was causing the destruction of the creature by Dispelling a Bull's Endurance off of it. If someone caused a destruction event without using an attack or a spell cast, such as by revealing an enchantment instead, then you would not get any opportunity to reveal Rise Again as the destruction would resolve before you got that chance.
