GMAT Prep: she was less successful after

[Sage Pearce-Higgins]

I agree with you in this case that 'after' is incorrect. However, I strongly advise you against relying on redundancy to eliminate answer choices in 99% of cases. In my experience students often become worse at solving SC problems if they do so.

[RAHULS852]

Yes stick to basic errors of SC (Grammar & meaning).

Got your point. Thanks

Regards,
Rahul Singh

[Sage Pearce-Higgins]

You're welcome.