The most important force causing net outward water flow across capillary walls is

A. Glomerular filtration rate will increase: Vasoconstriction of the efferent arteriole increases resistance, raising glomerular pressure and increasing GFR.
B. Urine output will increase: Increased GFR results in more filtrate, which can lead to increased urine output.
C. Systemic blood pressure will go up: This is unlikely to be directly caused by local vasoconstriction of the efferent arteriole. Systemic BP is mainly influenced by overall vascular resistance and cardiac output.
D. Net filtration pressure will increase: Efferent arteriole constriction backs up pressure in the glomerulus, increasing net filtration pressure.

A. Because it saves one step in its synthesis: Zymogen secretion is about preventing premature activation, not simplifying synthesis.
B. So it will start digesting intracellular proteins of the chief cells more quickly: This would be harmful-zymogens prevent self-digestion of the cells that produce them.
C. So it acts only in the stomach lumen and does not digest intracellular proteins: Pepsin is secreted as inactive pepsinogen to prevent it from digesting the proteins inside chief cells. It is only activated to pepsin in the acidic environment of the stomach lumen.
D. So it can start digesting dietary proteins more quickly: Speed is not the reason for secreting it as a zymogen-safety is.