Saving modified buffer

[KYkid85]

I want to save an adjustment i made in $ sudo nano /boot/config.txt

So I....
CtrlX

"Save Modified Buffer" - I click yes

Here is where my question is

"File name to write: /boot/config.txt" - Then it gives me multiple options
-M-D DOS Format
-M-M Mac Format
M-A Append
M-P Prepend
M-B Backup File

What do I do here? And how do i execute the correct answer...In case its complicated?

-thanks!!

[rpdom]

You should be able to just hit Enter and the file will be saved in the default format.

[KYkid85]

Thank you for answering all my dumb questions! I'm basically one week in and starting to get a hang of this