(A) supercomputer that could eventually complete one quintillion operations per second and help –
CORRECTBoth features of supercomputer – “to complete one quintillion operations per second” and “to help” are expressed clearly and are parallel
(B) supercomputer that could eventually have the capability of completing one quintillion operations per second and
to help –
INCORRECTParallelism error – “to help” is not parallel to “eventually have the capability..” in the list beginning with “that could” as common term
Quality error – “have the capability to complete” is unnecessarily wordy. Same idea can be expressed succinctly by saying “it could eventually complete”
(C) supercomputer, eventually able to complete one quintillion operations per second,
and helping –
INCORRECTConstruction error – comma + and is used to connect two independent clause. Here “comma + helping” is not an IC but a verb-ing modifier
(D) supercomputer, and it eventually could complete one quintillion operations per second and
helping –
INCORRECTParallelism error – “helping” is not parallel to “complete.” in the list beginning with “it eventually could” as common term
(E) supercomputer, and it could eventually
have the capability to complete one quintillion operations per second and help –
INCORRECTQuality error – “have the capability to complete” is unnecessarily wordy. Same idea can be expressed succinctly by saying “it could eventually complete”