Common Katana's ability

[cmevans2]

Common version's card text:

"While a Katana die is in your Prep Area, if your opponent rolls one or more ? (even if they would reroll that die), you may pay 1 life and field one Katana die at level 1."

My question is: Does the Katana you field have to be from the prep area? Or could it be from your bag, reserve pool, used pile, or card?

[dmrulesteam]

Common version's card text:

"While a Katana die is in your Prep Area, if your opponent rolls one or more ? (even if they would reroll that die), you may pay 1 life and field one Katana die at level 1."

My question is: Does the Katana you field have to be from the prep area? Or could it be from your bag, reserve pool, used pile, or card?

The Katana die must be from your Prep Area.

-The Dice Masters Rules Team