A 45-year-old microbiologist studies a bacterial mutant with a lethal defect preventing chromosome replication. The organism shows BP 120/80, HR 78, RR 16, Temp 37°C. DNA analysis reveals accumulation of short Okazaki fragments (800–1000 bp) with retained RNA primers at 5' ends. PCR confirms normal DNA polymerase III activity. Gel electrophoresis shows fragmented DNA without ligation. The mutation most likely affects which of the following gene products?

1. A)DNA ligase
2. B)Primase
3. C)DNA helicase
4. D)DNA gyrase
5. E)DNA polymerase IGABARITO