遗传性血管神经性水肿的发生机制是()

A．C2a产生过少

B．C2a产生过多

C．C3a产生过少

D．C3a产生过多

E．C4a产生过多

Which of the following is the most appropriate title for the passage

Which of the following countries is NOT mentioned in the passage

A．Fiji.
B．The Philippines.
C．New Zealand.
D．Australia.