Which of the following cases held that the retroactive nature of the act of recognition of a new…

In Civil Air Transport Inc. v. Central Air Transport Corporation, [1953] A.C. 70, the Privy Council addressed the scope and limits of the retroactive effect of recognition of a government, holding that while recognition of a new government operates retroactively to validate the acts of that new government from its inception, it does not retroactively invalidate lawful transactions entered into by the previous de jure government while it was still recognized. By contrast, Luther v. Sagor, [1921] 3 K.B. 532 established the basic principle that recognition of a de facto or de jure government retroactively validates its own internal acts within its territory, without addressing the validity of acts of a predecessor de jure government. Trendtex Trading Corporation v. Central Bank of Nigeria concerns restrictive sovereign immunity and the incorporation of customary international law, while Nicaragua v. U.S.A. concerns the use of force and non-intervention.