Answer:
DNA polymerase.
Step-by-step explanation:
DNA replication may be defined as the process of formation of daughter DNA from the template DNA strand. The process of DNA synthesis occurs in the 5' to 3' direction.
The enzyme responsible for DNA replication is DNA dependent DNA polymerase or DNA polymerase. This enzyme moves in 5' to 3' direction. DNA pol III is main replicating enzyme in prokaryotes and DNA pol alpha initiates DNA replication in eukaryotes.
Thus, the correct answer is option (a).