Complete the following paragraph by selecting the option that correctly fils the blanks (i)- (iv) The kidney have built-in mechanisms for the regulation of glomerular filtration rate. One such efficient mechanism is carried out by (i)._____ It is a special sensitive region formed by cellular modifications in the (ii)._________ and the (iii)._________ at the location of their contact. A fall in GFR can activate the JG cells to release (iv).________ which can stimulate the glomerular blood flow the thereby brings GFR back to normal