This is an example of a copy and paste text using the keyboard short cut, "Ctrl + V" (Pressing both keys at the same time). And there is also a sample document attachment rendered in full size. Hope this helps.
To copy and paste text, after highlighting and selecting the text you want to copy, click back to the response box to make it active (cursor should be located where you want to paste the text). Do the keyboard shortcut key combination, “Ctrl + V” to paste the text. To show an example I will copy and paste this paragraph in the body of the response box after a short intro.
The attachment option is very restrictive in size and does not accept the newer docx formatting. The limit is 20kb which is really nothing but a paragraph of maybe no more than 5 lines. So instead of using attachment, unless your doc is really small but then if it is then you might just copy and paste it to the body of the response box.