The correct answer is strict meter and rhyme.
Postmodernism is all about innovation and breaking away from rules and tradition, so postmodern authors definitely didn't want their poems to have a strict meter and rhyme. Postmodern poems use free verse, with no strict rules when it comes to meter, rhyme, topics, language, etc. However, some of the most common postmodern characteristics are jumps in narration, experimentation, and multiple narrators.