Final answer:
Option (a), The presence of hemoglobin in urine is referred to as hemoglobinuria, indicating the presence of free hemoglobin frequently linked to diseases like malaria rather than RBCs or WBCs as in hematuria.
Step-by-step explanation:
The presence of hemoglobin in urine is referred to as hemoglobinuria. This condition is distinct from other urine abnormalities such as hematuria, which occurs when both red blood cells (RBCs) and white blood cells (WBCs) are found in the urine, often seen in conditions like nephritis and kidney stones.
In contrast, hemoglobinuria involves the presence of free hemoglobin in the urine, which can occur in diseases such as malaria or kala-azar. It is important to differentiate hemoglobinuria from myoglobinuria, which is the presence of myoglobin in urine and can be seen in muscle damage, and anuria, where there is no urine excretion, which can happen in conditions like acute renal failure.