**Core Concept**
Serum alkaline phosphatase (ALP) is a liver enzyme that catalyzes the hydrolysis of phosphate esters, playing a crucial role in bone mineralization and liver function. Elevated ALP levels are often indicative of bone or liver disease.

**Why the Correct Answer is Right**
The correct answer is related to the isoenzyme distribution of ALP in different tissues. ALP is composed of various isoenzymes, including bone, liver, and intestinal isoenzymes. In certain conditions, the bone isoenzyme may be elevated, while the liver isoenzyme remains normal or low. This is particularly true in cases of bone disorders such as Paget's disease, where the bone isoenzyme is predominantly elevated. Additionally, certain bone disorders like osteomalacia or rickets may also present with normal liver ALP levels.

**Why Each Wrong Option is Incorrect**
**Option A:** In this condition, both bone and liver ALP isoenzymes are typically elevated, making it an incorrect choice.
**Option B:** This condition is characterized by elevated liver ALP isoenzymes, not normal levels.
**Option C:** In this condition, both bone and liver ALP isoenzymes are typically elevated, making it an incorrect choice.

**Clinical Pearl / High-Yield Fact**
When interpreting ALP levels, it's essential to consider the isoenzyme distribution and the patient's clinical presentation. A normal ALP level in a patient with suspected bone disease may prompt further investigation into the specific isoenzyme distribution.

**Correct Answer: C.**