When the poet establishes a pattern of rhyme, usually marked by letters to symbolize correspondences, the reader can identify a. internal rhyme. b. rhyme scheme. c. rhythm. d. meter.

B: rhyme scheme

Explanation:

 A rhyme scheme is a regular pattern of rhyme at the end of the line of a poem. This pattern is demonstrated by the use of letters (beginning with "A") indicating the lines in a poem that rhyme with each other. For example:

[...] have you any wool ?  A

[...] three bags full !  A

[...] one for the dame B

[...] down the lane.  B

a. the man as a ruler

merry christmas to you, too. may god be with you all in doing your work and just living a great life in general! < 3