Respiratory tract histology

Steps:

• Identify trachea wall composition: pseudostratified ciliated columnar epithelium, cartilage rings, smooth muscle, and elastic fibers.
• Identify alveolus wall composition: simple squamous epithelium and elastic fibers for gas exchange.
• Compare for common or distinct tissues: trachea has supportive cartilage and muscle; alveoli prioritize thin diffusion barrier.
• Select option listing accurate tissues for both structures.

Not enough information: Choices B, C, D not provided.

Why A is correct:

• A matches standard histology, including ciliated epithelium in trachea and squamous epithelium in alveoli, per respiratory system anatomy definitions.

Why the others are wrong:

• B: Likely omits key epithelial types.
• C: Probably includes incorrect tissues like bone.
• D: May focus only on one structure, ignoring the other.

Final answer: A