For the following reaction, predict whether the major product will be a substitution product or an elimination product. Write the major product of the reaction.

Structure of a cyclohexane derivative with a missing substituent.

Structure of a cyclohexane derivative with a different substituent position.

Structure of a cyclohexane derivative with an O-tBu substituent.

Structure of a cyclohexane derivative with an O-tBu substituent in a different position.