Upon completing a room, if a room clear reward would spawn, another different reward spawns next to it. If Isaac takes/opens one, the other disappears.
If one of the rewards is a troll bomb, picking up the other reward will not make the troll bomb disappear.
If one of the consumables generated by this effect is a heart, converting it with Apple of Sodom or Keeper will not cause the other consumable to disappear.
If one of the consumables generated is a Haunted chest and is picked up and thrown by the Polty (thus opening its content), picking up the contents of the chest will not make the other consumable disappear, and taking the other consumable will only make the opened chest disappear.
If one of the consumables is a Stone Chest, blowing it to open it and picking up its contents will not make the other consumable disappear, and taking the other consumable will only make the opened chest disappear.
However, this doesn't apply if the Stone Chest has an item in it. Taking the other consumable will cause the Stone Chest item to disappear and vice versa.
Bag of Crafting: Both rewards can be collected in one scoop, although somewhat inconsistently.
Broken Padlock: Bombing any chest spawned by Options?, including the ones not requiring keys, allows picking up the contents of the chest without the other reward disappearing, unless the empty chest is touched. This can be easily avoided by simply exiting and reentering the room.
Contract From Below: Spawns a second set of consumables. The "Options?" consumable is not guaranteed to be the same for each copy of the original consumable. Each pair of consumables functions independently for "Options?" meaning Isaac can pick up one of the first two rewards and one of the second two rewards.
Deep Pockets: If multiple coins are generated, each one will have its own alternative reward.
Equality!: While Equality! is active, both rewards can be collected without the other despawning. Options? also makes Equality! easier to keep active
Guppy's Eye: Takes the guesswork out of choosing between a chest/sack and a pickup by allowing you to see what the chest/sack will give.
Guppy's Tail: Gives a choice between a golden chest and something else in case you are low on keys.
Magneto: Opening a chest does not make the other reward disappear. Picking up the other reward afterwards will only remove the empty chest, and picking up the contents of the chest will not make the other reward disappear, letting Isaac take both rewards. This does not apply to chests with items in them, which disappear or make the other reward disappear as normal. Touching a chest will still make the other reward disappear.
Broken Modem: If the room drops are doubled only the original set is affected by "Options?", both consumables of the duplicate set can be collected.
If Isaac has Guppy's Eye when a chest is spawned by Options? and Isaac picks up the other pickup that spawns, the visual showing the contents of the chest will remain on screen after the chest disappears.