Sentence Correction

to have read of how the critics scorned Mary Todd Lincoln as a trailor to her birth,how loyal Union citizens suspected her of treason and how many accused her of unpatriotic extravagance is to feel deeply how difficult life was even for the aristocracy of Civil was times

A
C to read of
D Reading about
E having read about

Isn't it read about the correct idiom?

I've never heard of anyone saying "read of". What is the source of this question?

Me too the question is from catprep and the anser choice is read of....