**Core Concept**
Glomerular injury leads to the loss of protein and albumin through the damaged glomerular basement membrane, resulting in the presence of protein in the urine. This is a hallmark of glomerular disease, such as nephrotic syndrome. The presence of specific proteins in the urine can help differentiate between glomerular and non-glomerular causes of proteinuria.

**Why the Correct Answer is Right**
Albumin is the most abundant protein in the blood plasma, and its presence in the urine is a sensitive indicator of glomerular damage. The glomerular basement membrane acts as a selective filter, allowing small molecules like water and ions to pass through while restricting the passage of larger molecules like albumin. In glomerular injury, the integrity of this filter is compromised, leading to the leakage of albumin into the urine. The presence of albumin in the urine is a reliable indicator of glomerular damage and is often used as a diagnostic criterion for conditions like nephrotic syndrome.

**Why Each Wrong Option is Incorrect**
**Option A:** Hemoglobin is not a specific marker for glomerular injury. Its presence in the urine can be due to various causes, including hemolysis, bleeding, or myoglobinuria. Hemoglobin is not selectively filtered by the glomeruli and is therefore not a reliable marker for glomerular damage.
**Option B:** Red blood cells are not typically found in the urine in conditions of glomerular injury. Their presence is more indicative of bleeding or hemolysis. Glomerular injury may lead to the presence of red blood cell casts, but this is a different and more specific finding.
**Option C:** White blood cells can be present in the urine due to various causes, including urinary tract infections or inflammation. Their presence is not specific for glomerular injury and can be seen in conditions affecting the lower urinary tract.

**Clinical Pearl / High-Yield Fact**
The ratio of albumin to creatinine in the urine can help differentiate between glomerular and non-glomerular proteinuria. A high albumin-to-creatinine ratio is indicative of glomerular damage, while a low ratio is more suggestive of non-glomerular causes of proteinuria.

**Correct Answer: C. Albumin**