单选题：In order to convert the infix expression `4 * 3 + (6 * 3 - 12)`

In order to convert the infix expression `4 * 3 + (6 * 3 - 12)` to postfix expression using a stack $$S$$, then the minimum size of $$S$$ must be: @[B](2)

A. 2
B. 3
C. 4
D. 5



A.2
B.3
C.4
D.5


答案：B