Which tree did God forbid Adam and Eve to eat from?

Answer: Tree of knowledge of good and evil

God commanded them not to eat from the tree of the knowledge of good and evil.

“And the LORD God commanded him, “You may eat freely from every tree of the garden, but you must not eat from the tree of the knowledge of good and evil; for in the day that you eat of it, you will surely die.””— Genesis 2:16-17 (BSB)