What are obligations incurred by a defaulting state?

The answer is indeed focused on the nature of obligations incurred by a defaulting state. When a state defaults, it typically engages in responsibilities that require immediate action, as these obligations are often legally binding and necessitate attention to resolve issues that have arisen from the default. This includes actions needed to mitigate any negative impacts and address the factors that led to the default in the first place.

In the context of the other choices, voluntary commitments that may be ignored do not accurately reflect the seriousness of the obligations of a defaulting state; these obligations are not optional and must be adhered to. Financial penalties may be one possible outcome of default; however, they are not the sole definition of the obligations themselves. Additionally, potential rewards for future compliance would not be applicable to obligations incurred as a result of prior defaults, as the focus is on rectifying past issues rather than incentivizing future behavior. Therefore, the emphasis on responsibilities requiring immediate action aligns most closely with the nature of obligations following a default.