GFR increases ifa) Efferent arteriole constrictsb) Efferent arteriole dilatesc) Afferent arteriole constrictsd) Afferent arteriole dilates

Increase in glomerular hydrostatic pressure increases the filtration, whereas decrease in glomerular osmotic pressure or increase in bowman’s capsule hydrostatic pressure decreases the filtration.   Similarly, when afferent arterioles constrict, there is less flow to the glomerulus and less glomerular hydrostatic pressure, consequently less filtration. Whereas, when efferent arterioles constrict, there is increased hydrostatic pressure in the glomerulus resulting in increased filtration.