Final answer:
Replication in most organisms is bidirectional from the origin. The leading strand is synthesized continuously towards the replication fork while the lagging strand is synthesized discontinuously in Okazaki fragments, both in a 5' to 3' direction. The correct option is D.
Step-by-step explanation:
In the context of DNA replication, the correct answer to the question is: In most organisms, replication proceeds in a bidirectional manner from the origin of replication.
The replication proceeds in this bidirectional manner because DNA polymerase, which is responsible for synthesizing new DNA strands, reads the template strand in the 3' to 5' direction and adds nucleotides only in the 5' to 3' direction.
The strand that is synthesized continuously towards the replication fork is known as the leading strand, while the strand synthesized discontinuously, away from the replication fork in short stretches called Okazaki fragments, is known as the lagging strand.