In the ASYLUM CASE (Colombia v Peru), 1950 ICJ Rep 266, the ICJ addressed the question of DIPLOMATIC ASYLUM. The Court held that:

1. The Asylum Case (Colombia v. Peru, 1950) concerned Colombia's grant of asylum in its Lima embassy to the Peruvian opposition leader Haya de la Torre. 2. The ICJ held: DIPLOMATIC ASYLUM is NOT a well-established rule of general international law. Colombia's claim that there existed a Latin American regional custom failed because the practice was not consistent and uniform. 3. The Court emphasised that the party invoking a custom must prove that the custom is established in such a manner that it has become binding on the other Party. 4. The case is significant for the test it applied to PROVE custom — particularly REGIONAL or BILATERAL custom. 5. Hence option B is correct. _Source: UN Charter 1945 / VCLT 1969 — Asylum Case (Colombia v Peru), 1950 ICJ Rep 266_