The software structure is an expression of the relationship among software modules. In the following phrases, which are NOT the relations among software modules (2 Points) Ⅰ. calling relation Ⅱ. belonging relation Ⅲ. Execution relation Ⅳ. process relation
A．Ⅰ and Ⅱ
B．Ⅱ and Ⅲ
C．Ⅲ and Ⅳ
D．none