The incorrect statement(s) about structural isomers of compounds having chemical composition ${\mathrm{C}}_5{\mathrm{H}}_{12}\mathrm{O}$ is/are.

One of its isomers has four methyl groups

None of its isomer pairs is metamers

It has eight isomers capable of forming intermolecular hydrogen bonds amongst themselves

Six of its isomers are only hydrogen bond acceptor but not hydrogen bond donor