Final answer:
Acid rain, which results from sulfur dioxide and nitrogen oxides emissions and is intensified by climate change, can erode physical structures and damage forested biomes. The correct option is A.
Step-by-step explanation:
The phenomenon capable of eroding physical structures and compromising the viability of forested biomes is acid rain. Acid rain is formed when emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx), primarily from the combustion of fossil fuels, interact with the water vapor in the atmosphere to produce sulfuric and nitric acids.
These acids then precipitate out, often far from the source of the pollutants, damaging both manmade structures and natural ecosystems. Acid rain corrodes materials like marble and limestone and makes trees more susceptible to drought and insect infestation, while also depleting soil nutrients.
Additionally, climate change, exacerbated by the burning of fossil fuels and deforestation, further stresses both manmade and natural systems, though it is a broader concept than acid rain itself. The correct option is A.