Final answer:
The D100 is the item that combines the uses of the D4, D6, and D20, and it rerolls your current items and pickups in the room. It is unlocked by completing the Boss Rush with The Lost, so the correct answer is B) D100.
Step-by-step explanation:
The item you're referring to is called the D100. It is a special item in the game The Binding of Isaac: Rebirth. When used, it has the combined effects of the D4, which re-rolls each of your current passive items, the D6, which re-rolls all pedestal items in the room, and the D20, which re-rolls all pickups in the room.
This item is unlocked by completing the Boss Rush with The Lost. Therefore, the correct answer to the question is option B) D100.