GMAT Sentence Correction (SC) | Re: Travelers to Mars would have to endure low levels of gravity

Parallelism:
endure X, avoid Y, contend Z, and perhaps ward off T
Only C is correct.

Travelers to Mars would have to endure low levels of gravity for long periods of time, avoid large doses of radiation,contend with the chemically reactive Martian soil, and perhaps even having to ward off contamination by Martian life-forms.


(A) contend with the chemically reactive Martian soil, and perhapseven having to ward
(B) contend with the chemically reactive Martian soil, and perhaps evenwarding