Which of the following best describes the orientation of antiparallel strands in DNA in terms of the 3' and 5' ends?

• A. Both strands run from 3' to 5'.
• B. One strand runs from 3' to 5'; the other from 5' to 3'.
• C. Both strands run from 5' to 5'.
• D. One strand runs from 5' to 3'; the other from 5' to 5'.

Answer: (B)