Please choose the correct solution to the question: soften butter

Solution1: pour a few cups of very hot (just below boiling) water into a double boiler or a saucepan with a metal bowl nested inside. Put the butter over the water bath and allow to soften. Keep an eye on it so the butter doesn’t start to melt.

Solution2: pour a few cups of very hot (just below boiling) water into a double boiler or a saucepan with a paper bowl nested inside. Put the butter over the water bath and allow to soften. Keep an eye on it so the butter doesn’t start to melt.

Answer format: solution1/solution2
Answer: solution1