During class, the teacher draws a flow chart on the blackboard to show the structure and i

During class, the teacher draws a flow chart on the blackboard to show the structure and its inner connection of a passag。What class do you think is it most possible be？

A.Word class.

B.Reading and speaking class.

C.Grammar class

D..Phonetics class.

请帮忙给出正确答案和分析，谢谢！