7. A firm that specializes in the analysis of handwriting claims from a one-page writing sample that it can assess more than three hundred personality traits, including enthusiasm, imagination, and ambition.

(A) from a one-page writing sample that it can assess
(B) from a one-page writing sample it has the ability of assessing
(C) the ability, from a one-page writing sample, of assessing
(D) to be able, from a one-page writing sample, to assess
(E) being able to assess, from a one-page writing sample,

I marked the answer as E. But OA is D. While solving, I was confused between C, D and E. I thought E was the most clear one.

Could someone tell me why E is wrong?