Final answer:
b) hair shaft
The follicle's shape affects the hair shaft's shape; this is the part of the hair exposed above the skin and is composed of dead cells.
Step-by-step explanation:
The shape of the hair follicle will determine the shape of the hair shaft as it grows from the hair follicle. The hair shaft is the part of hair that is visible above the skin surface and consists of dead cells. This keratinous filament begins its growth at the hair bulb, where the hair matrix containing a layer of basal cells is found. As these cells divide, they push the shaft upward through the follicle, causing the hair to grow. Importantly, hair texture, whether it's straight or curly, is determined by the shape and structure of the follicle and the cortex layers within the hair itself.