Answer
trans and cis 2-butenes
Work Step by Step
1) Recall the Zaitsev rule
It says the more substitued double bond will be obtained, therefore product is 2-butene ( not 1-butene)
2) Cis/trans isomerism
Groups attached to a double bond could be by one side or opposite to each other, so firstly, put 2 methyl groups together (cis), then on the opposite sides ( trans )
