Detailed Explanation:

In genetic disorders, chromosomal abnormalities play a critical role. Let’s match the correct genetic syndromes with their corresponding chromosomal conditions based on the provided options:

1. Down Syndrome (A) is caused by Trisomy 21, which is the presence of an extra chromosome 21 (i.e., XX+21). This condition is the hallmark of Down syndrome.

2. Edward Syndrome (B) is caused by Trisomy 18, where there are three copies of chromosome 18 (i.e., Trisomy 18).

3. Klinefelter Syndrome (C) is characterized by the presence of an extra X chromosome in males, typically XXY.

4. Turner Syndrome (D) occurs in females who have only one X chromosome, resulting in a chromosomal pattern of 45, X (i.e., Female with one X).

With this in mind, the correct matching is:

Answer: B. A-IV, B-II, C-III, D-I

This means:

• Down Syndrome (A) matches with XX+21 (IV).

• Edward Syndrome (B) matches with Trisomy 18 (II).

• Klinefelter Syndrome (C) matches with XXY (III).

• Turner Syndrome (D) matches with Female with one X (I).