**Core Concept**
Chorionic villous sampling (CVS) is a prenatal diagnostic procedure that involves removing a sample of the placenta for genetic testing. It is typically performed between 10-12 weeks of gestation. The procedure can detect chromosomal abnormalities, such as **Down syndrome**, and other genetic disorders.

**Why the Correct Answer is Right**
Since the correct answer is not specified, let's discuss the general principles of CVS. The procedure involves inserting a catheter or needle into the uterus to collect a sample of chorionic villi, which are then analyzed for genetic abnormalities. This allows for early detection of potential issues, enabling parents to make informed decisions about their pregnancy.

**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific text, it's challenging to address each option directly. However, incorrect statements about CVS might include claims that it's performed later in pregnancy or that it's used to detect conditions that aren't genetically based.
**Option B:** Similarly, without the text, we can't address this option specifically, but an incorrect statement might involve the safety or the purpose of the procedure.
**Option C:** An incorrect statement could involve the timing or the method of CVS.
**Option D:** This option might be incorrect if it suggests that CVS is used for a purpose other than genetic testing or if it misrepresents the risks associated with the procedure.

**Clinical Pearl / High-Yield Fact**
A key point to remember about CVS is that it carries a small risk of **miscarriage**, estimated to be around 1%. Understanding the risks and benefits of CVS is crucial for counseling patients.

**Correct Answer:** Correct Answer: D. Not enough information provided to fill this section accurately.