Final answer:
1,2-dibromoethene can exist as cis and trans isomers due to the presence of different substituents on the carbon atoms of the double bond, allowing for different spatial configurations.
Step-by-step explanation:
The compound that can exist as cis and trans isomers from the choices given is 1,2-dibromoethene.
This is because cis-trans isomerism requires the presence of different substituents attached to the carbon atoms of a double bond, which restricts the rotation and allows for two different spatial arrangements of the atoms.
In 1,2-dibromoethene, there are two bromine atoms attached to the double-bonded carbons, allowing for one isomer with the bromine atoms on the same side (cis) and one with the bromine atoms on opposite sides (trans).