10. During DNA replication, one of the new strands of DNA is synthesized continuously, while the other is synthesized as a number of separate fragments of DNA that are subsequently linked by DNA ligase. This is because
a. replication starts at many points on the chromosome
b. RNA primers only anneal to one of the parental strands of DNA
c. DNA polymerase III only synthesizes DNA in the 3' - 5' direction
d. one of the parental strands is unwound slower than the other by helicase
e. DNA polymerase III only synthesizes DNA in the 5' - 3' direction