Which form of nitrogen can be used by plants and animals A ammonia B dna C nitrogen gas D nitrates

The form of nitrogen that can be used by plants and animals is **D nitrates**. Plants can absorb nitrates from the soil, and animals obtain nitrogen by consuming plants or other animals. While ammonia (A) can also be utilized by some organisms, nitrates are the primary form taken up by plants in the nitrogen cycle. Nitrogen gas (C) is not usable in its gaseous form by most organisms, and DNA (B) is not a form of nitrogen that is directly usable; instead, it contains nitrogenous bases that include nitrogen.