Isomers are different chemical substances that have different physical and chemical properties, but have the same molecular formula, that is, the same number of atoms of each chemical element.
First, let's see if both have the same molecular formula:
Compound 1: C4H8
Compound 2: C4H8
They have a double bond and have a double bond between the 2nd and 3rd carbons and the carbon is in the opposite direction. This is an indication of geometric isomerism. Geometric spatial isomers is a particular case of spatial isomerism in which isomers are formed by unsaturated open structures (composed of a double bond between carbons).
Therefore, they are cis and trans isomers.
Answer: B. Isomers.