Question

select the best evidence to support the statement that the narrator is usually very focused.
violists hate it when we violinists crack viola jokes. but my audition for the connecticut all - state high school orchestra is in ten minutes, and im trying to relax. i raise my bow above the strings, about to practice one last time. and thats when i hear it. this note,
this pure note, with a warm vibrato that could melt ice instantly, flows from a nearby trumpet. it floats across the room. my concentrations broken. thats never happened to me before.
i whirl around, looking for the source of the sound. which isnt easy, because there are at least fifty trumpet players scattered through the lobby, practicing the same fanfare passage from rimsky - korsakovs capriccio espagnol, op. 34.
from paula yoo, good enough. copyright 2008 by paula yoo

Explanation:

To support the statement that the narrator is usually very focused, we look for evidence showing a contrast (since the current situation breaks their concentration). The sentence "My concentration's broken. That's never happened to me before." implies that normally, their concentration isn't broken, meaning they are usually focused.

Answer:

My concentration's broken. That's never happened to me before.