In: Anatomy and Physiology
Answer will be option (a)
Explanation:: GFR simply means the filteration of blood through glomerular membrane.It directly related with kidneys proper functioning.
The GFR is depended on various factors directly or indirectly.
For calculating GFR........
GFR = filtration coefficient × (hydrostatic glomerular pressure -hydrostatic bowman's capsule pressure)-( osmotic pressure of glomerular + Osmotic pressure of bowman's capsule)
When Osmotic pressure were reduced it directly increases GFR because it is the force exerted by proteins( present in blood) against the hydrostatic pressure of filteration.so if osmotic pressure decrease GFR increase and vice a versa.
Decreasing cardiac output directly decrease GFR by decreasing transportations of renal filterates through blood and fluids ..
If capillary permeability decrease,no filteration occur smoothly, resulted into decrease GFR.
Mean arterial pressure is independent of GFR rate, it ranges between 80 to 180 mm of Hg,if MAP below 80 then GFR decrease but if more than 180 it does not increase GFR..so it ranges between this pressur..normally decrease GFR..not increases.