In this graph regarding starling curves, mild hemorrhage will cause stroke volume to shift from point X to point?

Ans. (a) Point A(Ref: Guyton 13th ed. p.119)Understanding starling curveConcept:Starling's law of the heart states that increasing preload increases the force of contractionStarling's curve is the plot of this preload Vs force of contractionSo, X axis is preload and Y axis is force of contractionRepresentatives for preload - X axis can be end-diastolic volume or central venous pressureRepresentatives for force of contraction - Y axis can be stroke volume or cardiac outputStarling curve shifts up and to the left means increase in contractility & decrease in after loadStarling curve shifts down and to the right means decrease in contractility & increase in after loadRegarding this question,Point marked X is the normal curveMild hemorrhage can lead to decrease in preload (venous return)A major Compensatory mechanism for Mild hemorrhage is sympathetic activation which causes increase in cardiac contractility & heart rate. So, the answer lies in upper curveSame cardiac output is achieved in spite of decrease in preload but by increase in cardiac contractility. So, the stroke volume (cardiac output) shifts to point A