'Aerial metagenomics' best refers to which one of the following situations?

Answer: A. Aerial metagenomics refers to collecting DNA samples from air to identify organisms in a habitat at one go. Aerial metagenomics (or environmental DNA / eDNA from air) is a non-invasive biodiversity sampling technique. Air filters capture biological particles (skin flakes, hair, pollen, microbial cells, faecal dust) drifting in the atmosphere of a habitat. Sequencing the captured DNA reveals which species are present in the area without ever observing them. The technique was demonstrated to detect mammals in zoos and forests with high sensitivity. This is an extension of waterborne eDNA (which has been used for fish surveys) into the air, opening new biodiversity monitoring possibilities especially for elusive or nocturnal species. Distractors fail: (B) Avian genetics is normal genomics, not aerial metagenomics. (C) Airborne blood sampling is not metagenomics; metagenomics = sequencing community DNA. (D) Drones for sample collection is field sampling, not metagenomics. Source: 2022 Nature papers on airborne eDNA / NCBSL research.