**Core Concept**
Human chorionic gonadotropin (hCG) is a hormone produced by the placenta during pregnancy. However, elevated levels of hCG can also be associated with certain types of cancers, including testicular carcinoma. This is because some tumor cells produce hCG, leading to increased levels in the blood.

**Why the Correct Answer is Right**
hCG is a marker for testicular carcinoma because some tumors produce hCG, which can stimulate the production of testosterone. This is often seen in non-seminomatous germ cell tumors, such as choriocarcinoma and embryonal carcinoma. The production of hCG by tumor cells can lead to elevated levels in the blood, which can be detected by laboratory tests. This makes hCG a useful marker for the diagnosis and monitoring of testicular carcinoma.

**Why Each Wrong Option is Incorrect**
**Option A:** Alpha-fetoprotein (AFP) is a marker for hepatocellular carcinoma, not testicular carcinoma.
**Option B:** Prostate-specific antigen (PSA) is a marker for prostate cancer, not testicular carcinoma.
**Option C:** Lactate dehydrogenase (LDH) is a marker for various conditions, including hemolytic anemia and myocardial infarction, but it is not specific to testicular carcinoma.

**Clinical Pearl / High-Yield Fact**
The "hCG-alpha-fetoprotein (AFP) tumor marker" rule is a useful mnemonic for remembering the most common tumor markers for testicular carcinoma: hCG and AFP.

**Correct Answer: C. hCG (human chorionic gonadotropin)**