DNA ligase helps in
A. Joining bits of DNA.
B. Splitting or separation of two strands of DNA.
C. Renaturation.
D. Denaturation.

Hint: DNA replication is the process through which DNA generates numerous copies of itself. It's a type of biological polymerization that goes through three stages: initiation, elongation, and termination. It's a process that's catalysed by enzymes. The major enzyme in the replication process is DNA polymerase. The three major phases in DNA replication are: initiation, elongation, and termination. DNA replication is a crucial function for an organism's cell development, repair, and reproduction.

Complete explanation:
Option A: DNA ligase is a kind of ligase that catalyses the creation of a phosphodiester link between DNA strands, making it easier to connect them together.
So, option A is correct.
Option B: Behind the topoisomerase, helicase separates the two strands of DNA at the Replication Fork. During DNA replication, this enzyme catalyses the addition of nucleotide substrates to DNA in the \[5\prime \] to \[3\prime \] orientation.
So, option B is incorrect.
Option C: The hydrogen bonds between two strands are destroyed during the denaturation process, resulting in two single strands. The DNA covalent bonds are intact.
So, option C is incorrect.
Option D: Annealing is another name for renaturation. The unwound strand of DNA rewinds and gives back the dsDN when the temperature and pH return to their biologically optimal levels.
So, option D is incorrect.

Hence, Option A) is the correct answer.

Note:
DNA replication is a semiconservative process in which multiple protein components, such as enzymes and RNA molecules, are employed to create a new complementary daughter strand from a parental strand (template). The process of DNA replication is heavily reliant on enzymes. Many enzymes are involved in DNA replication, including DNA-dependent DNA polymerase, helicase, ligase, and others. The principal enzyme among them is DNA-dependent DNA polymerase. DNA replication is a crucial function for an organism's cell development, repair, and reproduction.