The correct option is 2) a stanza.
It is used on poetry and is a grouped set of lines within a poem. They can have rhyme and metrical schemes but it is not strictly required. There are many forms of stanzas.
The term Stanza comes from the Italian language and it's similar to strophe but this one sometimes refers to an irregular set of lines, the opposite of a regular, rhymed stanza.
Hope this answer helps you. Regards.