Final answer:
Replication of the E. coli chromosome is bidirectional as it proceeds in both directions from the origin of replication, and it is discontinuous on the lagging strand due to the synthesis of Okazaki fragments.
Step-by-step explanation:
The correct answer to the student's question is D) Bidirectional; discontinuous.
During the replication of the E. coli chromosome, which is a double-stranded circular DNA molecule, replication begins at a specific location known as the origin of replication. From this starting point, replication proceeds bidirectionally, meaning that it goes in two opposite directions at the same time, thus creating two replication forks. Furthermore, the replication process is discontinuous on the lagging strand, where the DNA is synthesized in short segments known as Okazaki fragments before being joined together to form a continuous strand.