A) Daily read following stream
B) Daily look at popular photos
C) Weekly read following stream
D) Weekly look at popular photos
E) Monthly read following stream
F) Monthly look at popular photos
G) Never
G/Never. I don't have an account, nor do any of my friends I might be interested in following. Also, I think those photograph filters look terrible so the service itself doesn't really appeal to me.
G/Never, i never use the official instagram app to view the photos. I use better experience apps like flipboard for viewing, off late i have even stopped taking pictures via instagram