Final answer:
The correct option is c. Combinations represent the tradeoff between economic output and environmental protection.
The combinations on the protection possibility curve represent the tradeoff between economic output and environmental protection, indicating the opportunity costs of choices within the production possibility frontier.
Step-by-step explanation:
In the context of the tradeoff between economic output and environmental protection, the combinations on the protection possibility curve represent option (c), the tradeoff between economic output and environmental protection. The production possibility frontier (PPF) illustrates the different combinations of the two that a society can achieve, given its technological capabilities and resource constraints.
At one end of the PPF, we have a scenario like choice 'P' which indicates a high level of economic output at the expense of environmental protection. At the opposite end, choice 'T' represents a high level of environmental protection with a corresponding reduction in economic output. The PPF is a graphical representation that highlights the opportunity costs associated with increasing environmental protection, which typically requires a decrease in economic output.