The description of memorable, one- or two-line rhymes aligns with the definition of epigrams. An epigram is a brief, witty poem or saying, often used to convey a thought or observation in a concise and often satirical manner. They are typically notable for their sharpness and clarity, making them particularly memorable.
Couplets, while also short, are specifically pairs of rhymed lines, which is a slightly different structure since they can sometimes extend beyond just delivering a witty or poignant observation. Quatrains consist of four lines with specific rhyme schemes, adding complexity that goes beyond the brief impact of an epigram. Stanzas refer to groups of lines in poetry, without the specific connotation of being memorable or particularly witty.
In summary, the defining characteristics of epigrams—briefness and wit—make it the correct answer in this case.