In the DNA double helix, what feature makes the two strands antiparallel?

• A. The major and minor grooves are produced because the strands run parallel and twist at different rates
• B. Hydrogen bonds between bases can only form if both strands have identical sequences in the same orientation
• C. Complementary base pairing (A with T and G with C) forces both strands to run in the same $5\prime \to 3\prime$ direction
• D. The two sugar-phosphate backbones run in opposite chemical directions because one strand is oriented $5\prime \to 3\prime$ and the other is oriented $3\prime \to 5\prime$ based on their phosphodiester linkages

Answer: (D)