Which of the following commands replaces each occurrence of ' bob ' in the file letter with ' Bob ' and writes the
result to the file newletter?
sed ' /bob/Bob ' letter > newletter
sed s/bob/Bob/ letter < newletter
sed ' s/bob/Bob ' letter > newletter
sed ' s/bob/Bob/g ' letter > newletter
sed ' s/bob, Bob/ ' letter > newletter