**Core Concept**
In syphilis, cerebrospinal fluid (CSF) examination is crucial for diagnosing neurosyphilis, which occurs when Treponema pallidum, the causative agent of syphilis, infects the central nervous system. CSF examination helps in identifying the presence of treponemal antibodies and detecting neurosyphilis, especially in patients with late-stage syphilis.

**Why the Correct Answer is Right**
CSF examination is indicated in adults with all stages of syphilis for early detection of neurosyphilis. This is because T. pallidum can infect the central nervous system at any stage of the disease, and CSF examination helps in identifying patients who require prompt treatment to prevent long-term neurological damage. The CSF examination involves testing for treponemal antibodies, such as the fluorescent treponemal antibody absorption (FTA-ABS) test, and measuring CSF protein and cell counts.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is correct; it is an indication for CSF examination in adults with all stages of syphilis.
**Option B:** This option is correct; it is an indication for CSF examination in adults with all stages of syphilis.
**Option C:** This option is correct; it is an indication for CSF examination in adults with all stages of syphilis.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that CSF examination is essential in diagnosing neurosyphilis, especially in patients with late-stage syphilis. The CSF-FTA-ABS test is a reliable indicator of neurosyphilis, and a positive result warrants prompt treatment with intravenous penicillin.

**Correct Answer:** D.