Only they were left in the store when the doors locked. what is the modifier or modifying phrase in the sentence?

a. store
b. doors
c. only

Read the excerpt. by my junior year i lived on campus all year round. between sorority life, political activism, boyfriends, and modern dance i couldn't stop moving. i came home for brief visits, but these visits were too awkward without rosalind. the house was profoundly still. mommy stayed in her room. russell didn't talk, let alone look at me. the chess set was still standing there, pieces and all! how does the author's word choice create an ominous tone in this excerpt?