From August 2021, which of the following countries requires a Green Card for vehicle insurance?

The correct response stands because Montenegro has been identified as a country that requires a Green Card for vehicle insurance starting from August 2021. A Green Card is an international insurance document that is recognized in many countries to prove that a driver has at least the minimum required insurance coverage.

Montenegro, while being a part of various international agreements concerning road transport, requires drivers entering its borders to present a Green Card as proof of insurance. This requirement enhances road safety and provides a clear framework for compliance with local insurance needs.

The other countries listed have different regulations concerning vehicle insurance, either not requiring the Green Card or having different stipulations for proof of insurance. For instance, Sweden operates under EU regulations that typically do not necessitate a Green Card for vehicles insured in other EU nations. Similarly, Luxembourg does not have a specific requirement for foreign vehicles to possess a Green Card. Turkey, while it does recognize the Green Card scheme, had different regulatory environments and requirements that do not align with the timeline provided in the question. Thus, Montenegro's specific requirement distinguishes it from the others listed.