The process in which the DNA is replicated and two copies are synthesized is called DNA replication. It involves the formation of replication fork. The two strands of the DNA helix separate and the new strands are formed on the original strands, known as the template strands. The strand which is synthesized in 3'-5' direction is the leading strand and the strand which is synthesized in the opposite direction is the lagging strand which contains the Okazaki fragments. This strand is synthesized away from the replication fork. Thus, the correct answer is option B

During DNA replication, Okazaki fragments are used to elongate the lagging strand away from the replication fork.

DNA replication is the process by which a cell makes an identical copy of its DNA. It is a crucial step in cell division and is essential for the transmission of genetic information to daughter cells. The replication of DNA involves the synthesis of two new strands, the leading strand, and the lagging strand.

Leading Strand:
The leading strand is synthesized continuously in the 5' to 3' direction, which is the same direction as the replication fork. DNA polymerase III, the main enzyme involved in DNA replication, synthesizes the leading strand by adding nucleotides complementary to the template strand.

Lagging Strand:
The lagging strand is synthesized discontinuously in the opposite direction of the replication fork. This is because DNA polymerase III can only synthesize DNA in the 5' to 3' direction, but the replication fork moves in the opposite direction. Therefore, the lagging strand is synthesized in short fragments called Okazaki fragments.

Okazaki Fragments:
Okazaki fragments are short DNA fragments that are synthesized on the lagging strand during DNA replication. These fragments are typically around 1000-2000 nucleotides long in prokaryotes and around 100-200 nucleotides long in eukaryotes. They are named after the Japanese scientist Reiji Okazaki, who first discovered them.

Synthesis of Okazaki Fragments:
The synthesis of Okazaki fragments involves several steps:
1. Priming: An RNA primer is synthesized by the enzyme primase, which provides a starting point for DNA synthesis.
2. DNA Synthesis: DNA polymerase III adds nucleotides to the RNA primer, synthesizing a short DNA fragment.
3. RNA Removal: The RNA primer is removed by the enzyme RNase H, leaving a gap in the DNA.
4. Gap Filling: DNA polymerase I fills in the gap by adding nucleotides complementary to the template strand.
5. Fragment Joining: The newly synthesized Okazaki fragment is joined to the previous fragment by the enzyme DNA ligase.

Elongation of the Lagging Strand:
Okazaki fragments are used to elongate the lagging strand away from the replication fork. As the replication fork moves, new RNA primers are synthesized, and DNA polymerase III adds nucleotides to these primers, synthesizing new Okazaki fragments. These fragments are then joined together to form a continuous strand by the action of DNA ligase.

In summary, during DNA replication, Okazaki fragments are used to elongate the lagging strand away from the replication fork. These fragments are synthesized in a discontinuous manner and are joined together to form a continuous lagging strand.