Several temperature-sensitive mutant strains of E. coli display the following characteristics.

Mutant (a): Newly synthesized DNA contains many mismatched base pairs.
Mutant (b): Okazaki fragments accumulate, and DNA synthesis is never completed.
Mutant (c): No initiation occurs.
Mutant (d): Synthesis is very slow.
Mutant (e): Supercoiled strands remain after replication, which is never completed.

What enzyme or function is being affected in Mutant (a), causing many mismatched base pairs?

a. No DNA repair
b. No Primase activity
c. No DNA gyrase activity
d. Only DNA polymerase I activity
e. No DNA ligase activity