If you don't want students to cheat or share answers then you wouldn't be getting the questions from a published textbook, regardless of if it was open or propr

If you don't want students to cheat or share answers then you wouldn't be getting the questions from a published textbook, regardless of if it was open or proprietary. How does a proprietary textbook solve the cheating problem? Even a new copy yearly doesn't do much of anything, students can still share answers or pay a third party to answer the questions on their behalf.