Nicotine's cardiovascular stimulant effects

Steps:

• Identify nicotine as the primary addictive stimulant in cigarette smoke.
• Recall nicotine constricts blood vessels and triggers adrenaline release.
• Link this to increased heart rate and blood pressure.
• Compare to other risks, which stem from tar, carcinogens, or carbon monoxide.

Why C is correct:

• Nicotine acts as a stimulant, causing vasoconstriction and elevated adrenaline, which directly raises blood pressure per cardiovascular physiology.

Why the others are wrong:

• A: Bronchitis and emphysema result from tar and irritants damaging lung tissue, not nicotine.
• B: Airway cancer is caused by polycyclic aromatic hydrocarbons and other carcinogens in smoke.
• D: Reduced birth weight links to carbon monoxide reducing fetal oxygen, with nicotine playing a secondary role.

Final answer: C