In a population survey, two malnourished children are identified: Child A with severe wasting and Child B with edema and fatty liver. Break down the physiological mechanisms that explain why Child B develops edema while Child A does not.

• A. Child B's edema is due to lymphatic obstruction from parasitic infection unrelated to nutrition, while Child A's wasting results from a genetic inability to store fat despite adequate protein intake.
• B. Child B (kwashiorkor) likely has hypoalbuminemia due to inadequate dietary protein leading to reduced plasma oncotic pressure and fluid shift into interstitial spaces causing edema; Child A (marasmus) has overall caloric deficiency with loss of fat and muscle but relatively preserved oncotic pressure, so edema is absent.
• C. Child B develops edema from excessive sodium intake that draws water into tissues, whereas Child A lacks edema because of hyperproteinemia that increases plasma oncotic pressure and restricts fluid movement into interstitial spaces.
• D. Child B shows edema because of high carbohydrate diets that directly cause fluid retention in adipocytes, while Child A does not because carbohydrates are low and do not affect oncotic forces.

Answer: (B)