检查厚壁轴瓦有无脱壳的方法是（）。

A．听响法

B．观察法

C．渗透探伤

D．磁粉探伤

Object-oriented analysis (OOA) is a semiformal specification technique for the object-oriented paradigm. Object-oriented analysis consists of three steps. The first step is (96) . It determines how the various results are computed by the product and presents this information in the form of a (97) and associated scenarios. The second is (98) , which determines the classes and their attributes, then determines the interrelationships and interaction among the classes. The last step is (99) , which determines the actions performed by or to each class or subclass and presents this information in the form of (100)

A．activity diagram

B．component diagram

C．sequence diagram

D．state diagram