Read the poem and then answer the question: When forty winters shall besiege thy brow
And dig deep trenches in thy beauty's field,
Thy youth's proud livery, so gazed on now,
will be a tatter'd weed, of small worth held:
Then being ask'd where all thy beauty lies,
Where all the treasure of thy lusty days,
To say, within thine own deep-sunken eyes,
Were an ill-eating shame and thriftless praise.
How much more praise deserved thy beauty's use,
If thou couldst answer "This fair child of mine
Shall sum my count and make my old excuse."
Proving his beauty by succession thine!
This were to be new made when thou art old,
And see thy blood warm when thou feel'st it cold.

What is the rhyme scheme of the poem?
A. aabb codd eeff gg
B. dd
C. abab cded efef gg
D. abcd efgh ijkl mnop