**Core Concept**
Human chorionic gonadotropin (hCG) is a hormone produced by the placenta during pregnancy, essential for maintaining the corpus luteum and supporting fetal development. It has structural similarities to luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

**Why the Correct Answer is Right**
hCG plays a crucial role in pregnancy, stimulating the corpus luteum to produce progesterone, which maintains the endometrium and supports embryonic development. The hormone has a similar alpha subunit to LH and FSH but a unique beta subunit, allowing it to bind to the LH receptor and mimic LH's effects. This results in the continued production of progesterone by the corpus luteum, maintaining pregnancy until the placenta takes over this function.

**Why Each Wrong Option is Incorrect**
**Option A:** This statement is true about hCG, so it's not the correct answer to this question.
**Option B:** hCG is indeed produced by the placenta during pregnancy, so this statement is correct as well.
**Option C:** hCG does have a unique beta subunit, which distinguishes it from LH and FSH, making this statement incorrect.

**Clinical Pearl / High-Yield Fact**
hCG can be detected in the urine as early as 6-8 days post-ovulation, making it a valuable marker for early pregnancy diagnosis.

**Correct Answer:** C. hCG does have a unique beta subunit.