Which internal epidermal root sheath grows alongside the hair root and is formed by cells from the hair bulb?

The internal epidermal root sheath is the correct answer as it specifically refers to the structure that grows alongside the hair root and is formed by keratinized cells originating from the hair bulb. This sheath is crucial as it encases the hair as it passes through the follicle and plays a role in guiding the hair to the surface. The internal sheath is composed of three layers of cells, differentiating it from other sheath structures associated with the hair.

The other choices describe components associated with the hair follicle but do not fit the criteria of being an internal sheath formed from the hair bulb. The epidermal root sheath, while related, is a broader term that doesn’t specify the internal aspect. The outer sheath refers to the structure surrounding the follicle but lacks the specific interaction with the hair root. The dermal root sheath is another external layer that provides structural support but also does not form alongside the hair root itself. Thus, the internal epidermal root sheath is the precise structure being described in the question.