Density-dependent regulation can be affected by factors that affect birth and death rates such as competition and predation. Density-independent regulation can be affected by factors that affect birth and death rates such as abiotic factors and environmental factors, i.e. severe weather and conditions such as fire
The answer is D: poaching, since it harms wildlife and destroys ecosystems.
Most carbon atoms are carbon-12, and these have 6 neutrons, but carbon-14 has 8 neutrons (2 extra), thus C-14 is considered an isotope of the element carbon.