By william shakespeare

my love is strengthened though more weak in seeming,
i love not less, though less the show appear,
that love is merchandized, whose rich esteeming,
the owner's tongue doth publish every where.
our love was new, and then but in the spring,
when i was wont to greet it with my lays,
as philomel in summer's front doth sing,
and stops her pipe in growth of riper days:
not that the summer is less pleasant now
than when her mournful hymns did hush the night,
but that wild music burthens every bough,
and sweets grown common lose their dear delight.
therefore like her, i sometime hold my tongue:
because i would not dull you with my song.

what is the rhyme scheme of the sonnet?

a. abba abba cdec de
b. abab cdcd efef gg
c. abba abba cdcd cd
d. abab bcbc caba bb