Final answer:
The correct answer to the question is (b) Blood colloid osmotic pressure and interstitial fluid hydrostatic pressure are the forces that move fluid into the blood vessel.
Step-by-step explanation:
You asked which two forces tend to move fluid into the blood vessel. Blood colloid osmotic pressure and interstitial fluid hydrostatic pressure are the ones that help move fluid into the blood vessel. The blood colloid osmotic pressure is due to proteins in the blood that cannot cross the capillary walls, leading to a net movement of fluid from the interstitial space with lower protein concentration back into the capillaries.
Interstitial fluid hydrostatic pressure arises as fluid accumulates in the interstitial space, creating pressure that seeks to push fluid back into the capillaries. Thus, the correct answer is b: Blood colloid osmotic pressure and interstitial fluid hydrostatic pressure.