Final answer:
Lymph is most similar to blood plasma without red blood cells because it is a component of the interstitial fluid which mirrors the composition of blood plasma, except without plasma proteins. Lymph aids in maintaining extracellular fluid balance by returning proteins and fluid to the circulation.
Step-by-step explanation:
Among the choices provided, the one that is similar to lymph is d. blood plasma without red blood cells. Lymph is a watery fluid that flows through the lymphatic system, and it contains protective white blood cells but does not include erythrocytes (red blood cells). Its composition includes a water solvent containing amino acids, sugars, fatty acids, hormones, salts, and waste products from cells, mirroring the composition of blood plasma except for the absence of plasma proteins.
Lymph is considered part of the interstitial fluid, which itself is derived from blood plasma. The major distinction is that while plasma contains clotting factors and proteins, lymph does not. Interstitial fluid and lymph are in dynamic exchange, helping maintain extracellular fluid balance in the body by returning protein and excess interstitial fluid to the circulation.
The fluid component in a patient with bacterial meningitis (cerebrospinal fluid) is not the most similar to lymph, as cerebrospinal fluid bathes the brain and spinal cord and has a different composition and function than lymph. Similarly, stomach acid and sweat are not related to lymph in composition or function and hence are not similar to it.