Question

Which of the following techniques is key in the process of close reading?

Answer 1

Annotating is the closest technique in the process of close reading.

Annotating the process of writing detailed notes around said paragraph.  It doesn't just mean to take notes, you could also be highlighting or underlining some terms.  I can't clearly describe it because you can practically do anything here.

If you do a Google search for the definition of annotation, you get...
"a note of explanation or comment added to a text or diagram."