Which of the following commands replaces each occurrence of ‘bob’ in the file letter with ‘Bob’ and writes the result to the file newletter?
A. sed ‘/bob/Bob’ letter > newletter
B. sed s/bob/Bob/ letter < newletter
C. sed ‘s/bob/Bob’ letter > newletter
D. sed ‘s/bob/Bob/g’ letter > newletter
E. sed ‘s/bob, Bob/’ letter > newletter