In order to form polymers, we need to chain molecules together. This involves making bonds between them.
Shifting H’s around doesn’t accomplish anything.
Forming more double bonds will have the opposite result, as it would make the molecules more stable and less likely to react with each other.
Adding oxygen to the molecule no longer makes it polybutene. That would likely result in the formation of some sort of ether, as hey would react to form a C-O-C Bond.
The only answer left is A. In order to form polyalkenes, we have to break a double bond so that it’s available to form more covalent bonds.
Hope this helps
The symbol for the hydroxide ion is OH-