Tar's Respiratory Effects: Cilia Damage and Cancer Risk

Steps:

• Identify tar as a sticky residue from tobacco smoke that deposits in airways.
• Evaluate statement 1: Tar impairs cilia function, preventing mucus clearance and increasing infection risk.
• Evaluate statement 2: Tar does not protect lungs; it exacerbates damage by coating surfaces.
• Confirm statement 3: Tar contains carcinogens that promote chronic respiratory diseases like cancer.

Why C is correct:

• Statements 1 and 3 align with tar's documented role in ciliary paralysis and carcinogenesis per respiratory toxicology.

Why the others are wrong:

• A includes incorrect statement 2, overstating tar's effects.
• B omits valid statement 3 on cancer.
• D excludes accurate statement 1 on cilia damage.

Final answer: C