Final answer:
The ORC is the protein complex that sits on replication origins throughout the cell cycle and is necessary for initiating DNA replication at these specific sites.
Step-by-step explanation:
The correct answer to the question is C) Origin Recognition Complex (ORC). The ORC remains bound to replication origins throughout the cell cycle. When DNA replication is ready to be initiated, the ORC serves as the foundation for the assembly of additional proteins that together with helicase, load onto the DNA to begin the unwinding process. DNA polymerase, primase, and DNA ligase are all crucial enzymes in the DNA replication process, but they do not remain bound to the replication origins throughout the cell cycle. The ORC's role is vital for the precise initiation of the replication process at specific locations on the DNA.