It's option C. Dilation of the afferent arteriole.
This would cause an increase in glomerular filtration rate (GFR) & renal plasma flow (RPF).One of the major reasons behind this scenario is that the renal vascular resistance is lessened while the hydrostatic pressure is heightened if afferent arteriole gets dilated.
The answer to this is option C. Dilation of the afferent arteriole will increase the renal plasma flow and glomerular filtration rate. The reasons for this are the following: the renal vascular resistance is lessened while the hydrostatic pressure is heightened.
If the dilation of the efferent arteriole occurs, the RPF will increase but the glomerular filtration rate will be decreased. Hyperproteinemia will decrease the glomerular filtration rate. This is also the same as the other choice, ureteral stone. It will also decrease the glomerular filtration rate.
Dilation of the afferent arteriole -dilation of the afferent arteriole will increase both renal plasma flow (rpf) [because renal vascular resistance is decreased] and glomerular filtration rate (gfr) [because glomerular capillary hydrostatic pressure is increased]. dilation of the efferent arteriole will increase rpf, but decrease gfr. constriction of the efferent arteriole will decrease rpf (due to increased renal vascular resistance) and increase gfr. both hyperproteinemia (inc in the glomerular capillaries) and a ureteral stone (inc hydrostatic pressure in bowmans space) will oppose filtration and decrease gfr.