Answer: ababc.
Step-by-step explanation: When we want to determinate the rhyme scheme of a poem, we need to pay attention to the ending sound of each line and how it compares with the one of the other lines. In the given lines of Shakespeare's Sonnet 12, we have that the first and third line end with the same sound "time" and "prime". The second and fourth line also end with the same sound "night" and "white" and the last line has an unique ending sound "leaves" so the rhyme scheme would be: ababc.