The Emperor Augustus, it appears, commissioned
an idealized sculpture portrait, the features of
which are so unrealistic as to constitute what one
scholar calls an "artificial face."
A) so unrealistic as to constitute
B )so unrealistic they constituted
C )so unrealistic that they have constituted
D )unrealistic enough so that they constitute
E) unrealistic enough so as to constitute


Please explain option A and C ?
And please explain the difference between so X as to and so X that.