The Answer — Option 2 !! see below- source follows
“Bird–building collisions in the United States: Estimates of annual mortality and species vulnerability”, Condor, Volume 116, 2014,
Based on 23 studies, we estimate that between 365 and 988 million birds (median ¼ 599 million) are killed annually by building collisions in the U.S., with roughly 56% of mortality at low-rises, 44% at residences, and <1% at high-rises.