This article is about an item affecting Boss rewards. For a similar item affecting room clear rewards, see Options?. For a similar item affecting Treasure Rooms, see More Options.
Both items that appear after defeating a Boss in The Void are from random item pools. Likewise, both items that appear after defeating The Fallen are Devil Room items.
There is no effect on items dropped by Mini-Bosses.
There is no effect on what appears after defeating Mom, even if The Polaroid / The Negative have not unlocked (in which case only 1 Boss item will appear).
Does not retroactively affect Boss Rooms that had already been cleared prior to picking it up.
Crooked Penny / Diplopia: Both items are copied, allowing Isaac to take both copied items without the other disappearing. The original pedestals will function as normal, removing the other if one is collected.
Jacob and Esau: Both brothers can take one item each if they are lined up properly.
Boss Rush.
The Void are from random item pools. Likewise, both items that appear after defeating 
The Fallen are Devil Room items.
Mom, even if 
The Polaroid / 
The Negative have not unlocked (in which case only 1 Boss item will appear).
Boss Rooms that had already been cleared prior to picking it up.
Book of Revelations: Defeating a Boss after using the book at least once in the floor will spawn both a regular Boss pool item and either 
Ball of Bandages or 
Cube of Meat.
Crooked Penny / 
Diplopia: Both items are copied, allowing Isaac to take both copied items without the other disappearing. The original pedestals will function as normal, removing the other if one is collected.
Jacob and Esau: Both brothers can take one item each if they are lined up properly.
Satanic Bible: Both items will be Devil Room items; only one can be bought.
Vanishing Twin: The item which appears after defeating the copied boss is also affected.
More Options' description is "There's options". It's the other way around for this item.
Options 
Donation Machine Unlocks 
The Binding of Isaac: Rebirth
