Final answer:
In a bash script, to write "ABC" followed by a newline, use the command: printf "ABC\\". This is the proper syntax to produce the desired output to standard output.
Step-by-step explanation:
In a bash script, you can write the three letters "ABC", followed by a newline, to standard output using a few different commands. However, the correct way to do it, as per the options given, would be option B) printf "ABC\\". The command echo can also accomplish this task with just a slight modification: echo "ABC"
The printf command is quite versatile in bash and allows for the inclusion of escape characters such as \\ to represent a newline. Therefore, to answer your question, write printf "ABC\\" in your script to output "ABC" followed by a newline.