Hank is undergoing puberty. Some of his facial hairs, which were up to this point ______ hairs, are now becoming _______ hairs.

A. ground substance
This is a major component of the ECM, consisting of water, proteoglycans, and glycoproteins that fill the space between fibers and cells.

B. cytoplasmic inclusions
These are structures found inside the cell (e.g., glycogen granules, lipid droplets), not in the extracellular matrix.

C. fluid
Interstitial fluid (extracellular fluid) is part of the ECM and facilitates nutrient and waste exchange.

D. protein fibers
Collagen, elastic, and reticular fibers are key components of the ECM that provide strength, flexibility, and support.

A. osteogenesis imperfecta
This is brittle bone disease, caused by defective collagen, not muscle turning into bone.

B. osteopetrosis
This is a rare condition involving overly dense bones due to osteoclast failure, not soft tissue ossification.

C. chondroidal ossification
This is not a recognized clinical condition. Ossification of cartilage does occur in development but doesn’t describe Harry's case.

D. fibrodysplasia ossificans progressiva (FOP)
FOP is a rare genetic disorder where soft connective tissues such as muscles, tendons, and ligaments turn into bone, progressively restricting movement and ultimately leading to complications that may be fatal.

E. osteoarthritis
This involves cartilage degeneration at joints due to wear and tear-not ectopic bone formation in soft tissues.