Ans. (B) Increases renal blood flow(Ref: Goodman Gilman 12th/e p355; KDT 8th/e p146)Dopamine has dose dependent actionsLow dose (1-2 mcg/kg/min): It stimulates only D1 receptors leading to renal vasodilation and thus increase in renal blood flow.Medium dose (2-10 mcg/kg/min): It stimulates both D1 and beta 1 receptors means it will lead to inotropic action also.High dose (>10 mcg/kg/min): It stimulates Dl, beta 1 and alpha 1 receptors resulting in additional vasoconstriction.