Which factor is known to induce an increase in vascular resistance?

The correct choice is smoking, as it is well-documented that smoking leads to an increase in vascular resistance. When a person smokes, various substances in tobacco smoke cause vasoconstriction, which narrows the blood vessels and ultimately increases resistance to blood flow. Moreover, smoking can contribute to endothelial dysfunction and arterial stiffness over time, further compounding the problem of increased vascular resistance.

Exercise, while it temporarily increases blood flow demand, actually promotes vasodilation and can lead to a decrease in vascular resistance as the blood vessels widen to accommodate increased blood flow. Hydration is important for maintaining optimal blood volume and vascular function, and when properly hydrated, the body generally experiences lower vascular resistance. Weight loss typically reduces the burden on the cardiovascular system and can lead to decreased vascular resistance due to improved metabolic health and a reduction in inflammatory markers.