When Joshua challenged Israel to choose whom they would serve, how did the people reply?

Answer: They would never forsake the LORD

The people answered, "Far be it from us to forsake the LORD to serve other gods!" (KJV: "God forbid that we should forsake the LORD").

“But if it is unpleasing in your sight to serve the LORD, then choose for yourselves this day whom you will serve, whether the gods your fathers served beyond the Euphrates, or the gods of the Amorites in whose land you are living. As for me and my house, we will serve the LORD!””— Joshua 24:15 (BSB)