Which of the following is a biotic limiting factor for a plant population in an ecosystem?

Access to sunlight

Birds that disperse seeds

Availability of soil minerals

Disease-causing bacteria

Access to sunlight is an abiotic factor, so not that one.

Bird that disperse seeds seems a likely answer - the birds are biotic and they affect the plant population because of how they disperse seeds.

Availability of soil minerals is abiotic, not that one either.

Disease-causing bacteria is another likely answer because it's biotic and it definitely affects plant population.

I think D is correct because bacteria are a living (biotic) factor in ecosystems and they affect plant populations