Answer:The mere-exposure effect.
Explanation:
The mere-exposure effect is a pyschological state which makes us develop the love for something based on the mere fact that we have been exposed to it for a long time or we are more familiar with it. It is also referred to as the familiarity principle.
"after several months of commuting, she starts to like the apartment building and even considers renting an apartment there"
After a period of commuting in this building Susan is more familiar with the place and has developed the love for it such that she even want to rent an Apartment there. So the mere fact of exposure has made her like the place.