Which description defines a rhyme scheme?

Responses

a pattern based on the last sound of each line
a pattern based on the last sound of each line - no response given

the pattern of repetition of a letter sound
the pattern of repetition of a letter sound - no response given

the order of stressed and unstressed syllables
the order of stressed and unstressed syllables - no response given

the elements that emphasize sounds of words
the elements that emphasize sounds of words - no response given

A rhyme scheme is a pattern based on the last sound of each line.