Well "I" is the person and notes and margins is the number cuz theres more than one
Here is a website that will help you find the answer and understand the poem as well...
http://www.sparknotes.com/poetry/hopkins/section4.rhtml
If you do not wish to visit the site I believe the answer is A.
Because she is mourning her own mortality, because man is mortal.
Okay so the answer is 167