Doubt ---2 options

[anshulagarwal12]

Degler does more than merely summarizing existing research; he constructs a coherent picture of two centuries of studies dealing with the changing roles of women

a. Degler does more than merely summarizing
b. Degler has done more than a mere summarizing of
c. Degler does more than merely summarize

Here, I prefered merely over mere as I want to modify (summarizing or summarize) so b is out.

but cant choose between a and c

Kindly help.

[kartikshah]

Try saying this sentence alternatively in your head.
Degler does not merely summarize the existing research but also...
Degler does not merely summarizing the existing research but also..

Which one sounds correct to you?

If still in doubt, see the tense of "constructs" in the clause that follows after the semi colon; that should help resolve any confusion.