The presence of a central core called medulla is a characteristic microscopic feature of which fibre?

Arrange the following stages of the textile coloring and evaluation process in the correct chronological order: A. Deep penetration of dye molecules into the fiber's polymer system B. Grading of the visual results against standardized grey scales C. Addition of electrolytes to neutralize negatively charged fibers and increase attraction D. Exposure of the dyed fabric to standardized conditions using specialized laboratory equipment Choose the correct answer from the options given below:

Arrange the following operational steps in the precise sequential order of forming an uncut warp pile fabric. I. The let off motion causes the yarns from the warp pile beam to slacken while the ground warp beam remains under tension. II. The reed firmly beats up all three picks, forcing the slackened warp to form the pile loops. III. An extra set of warp yarns is woven into the fabric to form an additional warp pile beam. IV. The third filling yarn in the set is inserted into the structure. Choose the correct answer from the options given below: