一、Regarding to Vienna Convention on the Law of Treaties (VCLT), please answer the following question: State A has been a party to the VCLT since 3 September 1995, while State B has ratified the VCLT on 10 March 2009. On 15 March 2009, A and B conclude a treaty on the common use and regulation of transboundary water sources, which is called the Water Treaty. Is the VCLT applicable to this Treaty? (25 points)