Starling's Forces and Edema Steps:

• Fluid exchange follows Starling's equation: net filtration = (capillary hydrostatic - interstitial hydrostatic) - (plasma oncotic - interstitial oncotic).
• Increased net filtration causes more fluid to leave capillaries and accumulate in tissues, leading to edema.
• Evaluate options by their impact on oncotic pressures, which oppose filtration.
• Higher interstitial oncotic pressure reduces the gradient pulling fluid back into capillaries, increasing tissue fluid.

Why C is correct:

• Higher tissue protein concentration elevates interstitial oncotic pressure, decreasing (plasma oncotic - interstitial oncotic) in Starling's equation, which increases net filtration and tissue fluid accumulation.

Why the others are wrong:

• A: Lower blood pressure decreases capillary hydrostatic pressure, reducing net filtration and tissue fluid.
• B: Higher blood plasma protein concentration raises plasma oncotic pressure, increasing fluid reabsorption into capillaries.
• D: Lower tissue fluid protein concentration reduces interstitial oncotic pressure, enhancing the gradient for fluid reabsorption.

Final answer: C