**Core Concept**
The quadruple test is a prenatal screening test used to detect fetal abnormalities, particularly Down syndrome, neural tube defects, and other chromosomal abnormalities. It involves measuring the levels of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), unconjugated estriol (uE3), and inhibin A in maternal serum.

**Why the Correct Answer is Right**
The quadruple test is typically performed between 15 and 22 weeks of gestation. During this period, the placenta produces high levels of hCG, which stimulates the production of AFP. The levels of AFP, hCG, uE3, and inhibin A are then measured in maternal serum to assess the risk of fetal abnormalities. The test is most accurate when performed between 16 and 18 weeks of gestation.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the quadruple test is not typically performed before 15 weeks of gestation, as the levels of the measured substances may not be sufficient for accurate interpretation.
* **Option B:** This option is incorrect because the quadruple test is not typically performed after 22 weeks of gestation, as the risk of fetal abnormalities may be lower and the accuracy of the test may decrease.
* **Option C:** This option is incorrect because the quadruple test is not typically performed before 16 weeks of gestation, as the levels of the measured substances may not be sufficient for accurate interpretation.

**Clinical Pearl / High-Yield Fact**
The quadruple test is a screening test, not a diagnostic test, and should be followed by confirmatory testing, such as amniocentesis or chorionic villus sampling (CVS), if abnormal results are obtained.

**Correct Answer: A. 15-22 weeks of gestation.**