Correct Answer: i-d, ii-c, iii-b, iv-a

Solution : The correct answer is i-d, ii-c, iii-b, iv-a.

Helicase is responsible for unwinding the double-stranded DNA into single strands. It separates the two DNA strands by breaking the hydrogen bonds between them, creating a replication fork.

RNA primase is an enzyme that synthesizes short RNA primers complementary to the DNA template strands. These primers provide the starting point for DNA synthesis by DNA polymerase.

DNA polymerase is responsible for adding nucleotides to the growing DNA strand during DNA replication. It catalyzes the polymerization of nucleotides by forming phosphodiester bonds between them.

DNA ligase plays a critical role in sealing the nicks or gaps in the DNA backbone. It joins the 3' end of a new DNA fragment to the 5' end of the previous fragment, which helps in creating a continuous, intact DNA strand.