The correct option is answer A. The rhyme scheme of the excerpt from "The Monk's Tale" is ABAB, corresponding to the rhyming of the first and third lines and the second and fourth lines.
The lines "I will not lament" (A) and "and fell at last..." (A) rhyme with each other, and the lines "The griefs of those who stood in high degree"(B) and "To bring them out of their adversity" (B) rhyme as well.
So, the answer to the question is the rhyme scheme A (first and third lines) and B (second and fourth lines), which corresponds to ABAB.