Task: Question Answering
Input (English): Question: During the exchange process in the capillaries, the net active force that attracts fluid from the interstitial space back into the capillaries is: 
 Options:  <1> Gravity. <2> Osmotic pressure of interstitial fluid. <3> Colloidal osmotic pressure of the plasma. <4> Hydrostatic blood pressure. <5> Glomerular hydrostatic pressure.
Output (English): 3