Which of the following commands would replace "bob" with "Bob" in all instances and generate a new letter for printing?

An administrator has created a really long letter and after the administrator is done, notices that the
name “Bob” has been used many times. The administrator forgot to capitalize it in many instances.
Which of the following commands would replace “bob” with “Bob” in all instances and generate a
new letter for printing?

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