What source can be applied to international contract law in states that are signatories for the sale of commercial goods?

The correct answer is the United Nations Convention on Contracts for the International Sale of Goods (CISG), which is a key international treaty that governs international sales of goods between parties in different countries that have ratified it. This Convention provides a uniform framework for the performance and enforcement of international sales contracts, thereby facilitating cross-border trade by providing standards that can help minimize misunderstandings and disputes.

CISG addresses various aspects of the contract formation, the rights and obligations of buyers and sellers, and remedies for breach of contract. This helps harmonize laws related to international commercial transactions and provides a legal structure that both parties can rely on, contributing to increased predictability and stability in international trade.

Other options, while significant in their own domains, do not provide the primary legal framework specifically for international sales transactions. The Uniform Commercial Code primarily governs domestic transactions in the United States and does not have application in international contexts. The World Trade Organization focuses on trade agreements and policy among nations rather than individual sales contracts. Lastly, the International Chamber of Commerce Guidelines provide best practices and rules for commerce but do not carry the legal weight or specificity of the CISG in terms of binding laws governing international sales contracts.