**Core Concept**
The total iron binding capacity (TIBC) is a measure of all proteins available for binding mobile iron in the blood, including transferrin. It serves as an indirect indicator of iron deficiency and is closely related to the body's iron transport and storage mechanisms.

**Why the Correct Answer is Right**
TIBC is primarily composed of transferrin, a beta-globulin that binds iron with high affinity. The normal range for TIBC is typically 240-450 mg/dL. An elevated TIBC indicates iron deficiency, as the body produces more transferrin to capture available iron. Conversely, a decreased TIBC may suggest iron overload, where less transferrin is produced due to reduced iron availability.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect, as it does not specify a normal range for TIBC.
**Option B:** Incorrect, as a normal range for TIBC should be provided, not a numerical value.
**Option C:** Incorrect, as it does not accurately describe the normal range for TIBC.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that TIBC is an indirect indicator of iron status and should be interpreted in conjunction with other iron-related tests, such as serum iron and ferritin levels.

**Correct Answer: C. 240-450 mg/dL.**