**Core Concept**
Secondary amyloidosis, also known as AA amyloidosis, is a condition where deposition of amyloid fibrils occurs in various organs due to chronic inflammation or infection. This type of amyloidosis is often associated with chronic diseases that lead to sustained production of acute-phase reactants, such as serum amyloid A (SAA) protein.

**Why the Correct Answer is Right**
Secondary amyloidosis can occur in various chronic conditions characterized by sustained inflammation, including chronic osteomyelitis, rheumatoid arthritis, and leprosy. In these conditions, the chronic inflammation leads to increased production of SAA protein, which is then deposited as amyloid fibrils in various organs, including the kidneys, liver, and spleen. This process can result in organ dysfunction and failure.

**Why Each Wrong Option is Incorrect**
**Option A:** While chronic osteomyelitis is a cause of secondary amyloidosis, it is not the only condition associated with this condition.
**Option B:** Similarly, rheumatoid arthritis is also a known cause of secondary amyloidosis, but it is not the only condition listed.
**Option C:** Leprosy is another chronic infection that can lead to secondary amyloidosis, making this option also correct.

**Clinical Pearl / High-Yield Fact**
It is essential to recognize that secondary amyloidosis can occur in various chronic conditions, and a thorough medical history is crucial in diagnosing this condition. The presence of amyloidosis should prompt an investigation into the underlying cause of the chronic disease.

**✓ Correct Answer: D. All**