Filtrate is formed as fluid is forced through the walls of the glomerulus and

initially, collects in the structure indicated by the letter B

Explanation:

Filtrate is formed as fluid is forced through the walls of the glomerulus and, initially, collects in the structure indicated by the letter B.

Urine formed by a kidney collects in the renal pelvis before being drained from the kidney by the urethra and transported to the urinary bladder.

The process by which glomerulus filtration occurs is called renal ultrafiltration. The force of hydrostatic pressure in the glomerulus (the force of pressure exerted from the pressure of the blood vessel itself) is the driving force that pushes filtrate out of the capillaries and into the slits in the nephron.