Please choose the correct solution to the question: How do I add the butter to the biscuit crumbs when making chocolate nutella tart?

Solution1: Add in melted butter and process in the sifter until the butter is well incorporated and the crumbs look like wet sand.

Solution2: Add in melted butter and process in the food processor until the butter is well incorporated and the crumbs look like wet sand.

Answer format: solution1/solution2
Answer: solution2