Which three statements are valid hypotheses about how the presence of bird feeders affects bird populations?

A. The locations of bird feeders affect the migration patterns of birds.
B. If there is a bird feeder in the area, bird populations are more likely to be reduced by predators that hunt for prey at feeders.
C. Uneaten seeds from bird feeders are a nuisance because they spread nonnative plant species.
D. Are more bird feeders and larger bird populations found in urban or rural locations?
E. Hanging a bird feeder outside a window is a fun way to attract more birds to your neighborhood.
F. Bird feeders attract more nonnative birds than native birds.