The mechanisms of DNA synthesis differs between the two new daughter strands during replication. This is due to the fact that:

• A. one RNA primer attaches to the 5' end of the parent strand and the other primer to the 3' end.
• B. Both daughter strands can't extend toward the replication fork because there would not be room for two DNA polymerase enzymes.
• C. Both RNA primers attach to the 3' end of the template strands, which are at opposite ends from each other.
• D. The DNA strands run antiparallel to each other and the DNA polymerase can only add nucleotides to the 3' end of the growing strand.

Answer: (D)

Verified step by step guidance

1. Understand the concept of antiparallel strands: DNA is composed of two strands that run in opposite directions, meaning one strand runs 5' to 3' and the other runs 3' to 5'.
2. Recognize the role of DNA polymerase: DNA polymerase is the enzyme responsible for adding nucleotides to a growing DNA strand, but it can only add nucleotides to the 3' end of the strand.
3. Identify the leading and lagging strands: During replication, one strand (the leading strand) is synthesized continuously in the direction of the replication fork, while the other strand (the lagging strand) is synthesized in short segments called Okazaki fragments.
4. Explain the need for RNA primers: RNA primers are short sequences that provide a starting point for DNA synthesis. On the lagging strand, multiple primers are needed to initiate the synthesis of each Okazaki fragment.
5. Clarify the directionality of synthesis: The antiparallel nature of DNA and the 3' end requirement for DNA polymerase result in the leading strand being synthesized continuously and the lagging strand being synthesized discontinuously.