Unlike crested wheatgrass, an alien species from Siberia that forms on

There are two errors tested.
1. Comparison.
2. Parallelism. develop - grow

Unlike crested wheatgrass, an alien species from Siberia that forms only shallow roots and produces tall above-ground shoots, native North American grasses develop an extensive root system, allowing for greater enrichment of the soil, but not grow to be very tall.

A) native North American grasses develop and extensive root system, allowing for greater enrichment of the soil, but not grow to be very tall

B) native North American grasses develop and extensive root system, which allows for their greater enrichment of the soil, but without growing to be that - out due to error - 2

C) the root system of native North American grasses is extensive, allowing for greater enrichment of the soil, but they do not grow to be very out due to error - 1. crested wheatgrass compaired to root system of native North American grass

D) the root system of native North American grasses is more extensive,allowing for the greater enrichment of the soil,but these grasses do not grow to be very - out due to error - 1. crested wheatgrass compaired to root system of native North American grass

E) the extensiveness of the root system of the native North American grasses allows for their greater enrichment of the soil, but they do not grow to be that out due to error - 1. crested wheatgrass compaired to root system of native North American grass
Answer A
By the way the original question may contain a typo. I think it is "an extensive" not "and extensive".