Hey dudes.  I get in this spot a few times a day and i'm confused by how it's supposed to model:

Hero's range improves on the river to the point where he runs out of ~0EV bluffs to fill out a balanced betting range.  his next tier of hands are 1 pair hands that have a significant amount of equity to check back.

Does villain construct his defense vs our bet in a way that 

a) makes the 0EV hands in our range indifferent to checking or bluffing?

b) makes one of our 1 pair hands relatively indifferent to checking or bluffing (say our weakest 1 pair hand has 25% equity to check)

c) other