Which of the following statements is not true? ()

A、 The immunity of states is derived from the rules of public international law, and from the par in parem imperium non habet.
B、 The doctrine of immunities of states and their property is very important not only in private international law but also in public international law.
C、 China has not signed United Nations Convention on Jurisdictional Immunities of States and Their Property.
D、 China still claims to uphold " the Absolute Doctrine.”