Sentence Correction

The greatest road system built in the Americas prior to the arrival of Christopher Columbus was the Incan highway, which, over 2,500 miles long and extending from northern Ecuador through Peru to southern Chile.

a.
B. Columbus was the Incan highway, over 2,500 miles in length, and extended
c. Columbus, the Incan highway, which was over 2,500 miles in length and extended
d. Columbus, the Incan highway, being over 2,500 miles in length, was extended
E. Columbus, the Incan highway was over 2,500 miles long, extending

On the exam, i was looking at B or E
I chose B even though i felt over 2,500 miles in length seemed wordy and awkward.

I felt E was incorrect because extending means that it is still extending. but since we are talking past tense, does that mean we can assume that at the time it was built it extended, and no longer extends?

B. Columbus was the Incan highway, over 2,500 miles in length, and extended . Verb is missing after comma,
c. Columbus, the Incan highway, which was over 2,500 miles in length and extended. awkward construction. Already there is an opening modifier. again there is another modifier which.
d. Columbus, the Incan highway, being over 2,500 miles in length, was extended . changes the meaning.
E. Columbus, the Incan highway was over 2,500 miles long, extending . Opening modifier, followed by highway [subject] was 2,500 miles long, followed by 'ing modifier modifying the length.

GMAT Kolaveri wrote:B. Columbus was the Incan highway, over 2,500 miles in length, and extended . Verb is missing after comma,
c. Columbus, the Incan highway, which was over 2,500 miles in length and extended. awkward construction. Already there is an opening modifier. again there is another modifier which.
d. Columbus, the Incan highway, being over 2,500 miles in length, was extended . changes the meaning.
E. Columbus, the Incan highway was over 2,500 miles long, extending . Opening modifier, followed by highway [subject] was 2,500 miles long, followed by 'ing modifier modifying the length.

for B isn't extended the verb?

fangtray wrote:

GMAT Kolaveri wrote:B. Columbus was the Incan highway, over 2,500 miles in length, and extended . Verb is missing after comma,
c. Columbus, the Incan highway, which was over 2,500 miles in length and extended. awkward construction. Already there is an opening modifier. again there is another modifier which.
d. Columbus, the Incan highway, being over 2,500 miles in length, was extended . changes the meaning.
E. Columbus, the Incan highway was over 2,500 miles long, extending . Opening modifier, followed by highway [subject] was 2,500 miles long, followed by 'ing modifier modifying the length.

for B isn't extended the verb?

was the incan highway, x and y

x -was over 2,500
and
y -extended

The greatest road system built in the Americas prior to the arrival of Christopher Columbus was the Incan highway, which, over 2,500 miles long and extending from northern Ecuador through Peru to southern Chile.

a. Columbus was the Incan highway, which, over 2,500 miles long and extending
B. Columbus was the Incan highway, over 2,500 miles in length, and extended
c. Columbus, the Incan highway, which was over 2,500 miles in length and extended
d. Columbus, the Incan highway, being over 2,500 miles in length, was extended
E. Columbus, the Incan highway was over 2,500 miles long, extending

IMO: E