Well the sentence you refer to is correct.
However, probably you did not pay much attention. RC is tricky
She was also, in many ways, an early feminist, establishing largely unheard of employee benefits
She was ALSO clearly states an example or a FURTHER example of what she DID.
Adding "in many ways" reinforces our example even more
From this
(B) illustrate Vionnet’s admirable qualities
(E) provide details that bolster Vionnet’s feminist credentials
Clearly E is wrong because we do have an ULTERIOR example of her qualities. 1+1+1+1.................She had this, and this, and this, and this, and ALSO a feminist
She was NOT a feminist in a pure sense. However, from what she does, we could consider also her a precursor or foregoer of that specific movement
I hope this helps
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