The correct order of pK$$_a$$ values for the following compounds is:

A

c $$>$$ a $$>$$ d $$>$$ b

B

b $$>$$ d $$>$$ a $$>$$ c

C

b $$>$$ a $$>$$ d $$>$$ c

D

a $$>$$ b $$>$$ c $$>$$ d