**Core Concept**
The pH of synovial fluid is crucial for understanding joint health and disease. Synovial fluid, found in the cavities of synovial joints, plays a key role in reducing friction between the articular cartilage and other tissues. The **pH of synovial fluid** is slightly alkaline.

**Why the Correct Answer is Right**
The correct answer is related to the slightly alkaline nature of synovial fluid, which is necessary for the proper functioning of joints. This environment supports the activity of **enzymes** involved in the maintenance and repair of joint tissues. The pH of synovial fluid is around 7.3 to 7.4, which is close to neutral but slightly alkaline.

**Why Each Wrong Option is Incorrect**
**Option A:** Is too acidic for the normal functioning of synovial fluid.
**Option B:** Is too alkaline and not within the normal range.
**Option D:** Is not within the physiological range for synovial fluid.

**Clinical Pearl / High-Yield Fact**
The pH of synovial fluid can change in various joint diseases, such as **rheumatoid arthritis**, where it may become more acidic due to inflammation.

**Correct Answer: C. 7.4**