Final answer:
The correct option is c) Deforestation and loss of biodiversity.
Deforestation and loss of biodiversity is a human activity that decreases the environment's carrying capacity by disrupting ecosystems and reducing resources necessary for human survival.
Step-by-step explanation:
One human activity that has decreased the carrying capacity of the environment is deforestation and loss of biodiversity. Deforestation, often driven by the need to create space for agriculture and urban expansion, involves the removal of large areas of forest, which disrupts ecosystems and reduces biodiversity. This degradation of ecosystems can lead to soil erosion, decreased air and water quality, and reduced habitat for wildlife, including pollinators essential for many crops.
The loss of biodiversity also means the loss of potential natural resources, including plants and animals that might be utilized for food, medicine, or other human needs. Therefore, while some human activities, such as the implementation of sustainable agriculture or investment in renewable energy sources, work to increase the carrying capacity, others like deforestation lead to long-term detrimental effects that ultimately threaten the ability of the environment to support human populations.