The Average Mutation Rate for DNA Replication Is 1 Mutation

The average mutation rate for DNA replication is 1 mutation for every 10 billion (10,000,000,000) nucleotides of DNA replicated. Yet DNA polymerase makes a mistake during replication at an average of 1 in 100,000 nucleotides. What does this say about DNA replication?

A) Most errors in DNA replication become mutations.
B) The base-pairing rules (A pairs with T and G pairs with C) prevent any mutations.
C) Cells are extraordinarily proficient at repairing errors made during DNA replication.
D) Cells recognize that a small fraction of mutations are beneficial to organisms and do not repair those.