**Core Concept**
The human genome project involves understanding the structure and composition of DNA, including the base pairing rules: adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). The given DNA strand composition can be used to determine the composition of the complementary strand.

**Why the Correct Answer is Right**
Since A pairs with T and G pairs with C, the complementary strand will have 22 A (to pair with 22 T on the other strand, but given 20 T, it means 20 A will pair with 20 T and the rest of the A will pair with the rest of the T, implying an error in the question as it seems to imply 22 A will pair with 20 T which is incorrect, however, considering the base pairing rules for the given quantities: 20 T will pair with 20 A, 25 C will pair with 25 G, and the remaining bases will pair accordingly), 25 G (to pair with 25 C), 30 is incorrectly stated as C when it should be G to maintain the base pairing rule, and 20 T (to pair with 20 A). Thus, for a complete double-stranded molecule, the correct counts should reflect base pairing rules.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect due to misunderstanding of base pairing rules.
**Option B:** Incorrect as it does not follow the base pairing principle correctly.
**Option C:** Incorrect due to the same reasons as above.

**Clinical Pearl / High-Yield Fact**
Remember, in DNA, A always pairs with T, and G always pairs with C. This 1:1 ratio is crucial for understanding genetic material structure and function.

**Correct Answer:** D. 20 A, 30 G, 25 C, 20 T and the complementary strand will have 20 T, 25 G, 30 C, 22 is an error and should be 20 A.