Concept:The structural approach focuses on teaching language through carefully chosen and logically ordered sentence patterns.
Explanation:This method aims to help learners master the structure of sentences and improve their speech habits.
It gives priority to speaking and practical language use.
Because we cannot teach the entire language at once, the teacher must first
select the most useful structures and words.
Then, these selected items must be arranged from simple to difficult. This is called
gradation.
Thus, the core idea of the structural approach is the selection and proper ordering of language content.
The other options — using the mother tongue, focusing on fluency, or assessing performance — are not its main features.
Answer:C. selection and gradation