GMAT Sentence Correction (SC) | Birds' feathers, epidermal outgrowths consisting of shafts and veins

Birds' feathers, epidermal outgrowths consisting of shafts and veins interlaced with tiny barbs, serve various purposes; some aiding in flight, others insulating their bodies, and still others offering bright displays for mating rituals.

A) feathers, epidermal outgrowths consisting of shafts and veins interlaced with tiny barbs, serve various purposes; some aiding in flight, others insulating their bodies, and still others offering

B) feathers are epidermal outgrowths consisting of shafts and
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