The method for the acquisition of teaching skill is —

Concept: Micro-teaching is a controlled teacher-training technique in which a trainee practises one narrowly defined teaching skill — such as questioning, stimulus variation, explaining, or reinforcement — by teaching a short, scaled-down lesson to a small group of pupils, then receives supervised feedback and re-teaches the same skill to refine it.

Application: The question asks specifically for a method aimed at building the teacher's own teaching skill, not a method used to teach students. Micro-teaching is defined exactly as such a technique: it isolates one teaching skill, has the trainee practise it on a small group in a scaled-down lesson, and uses supervised feedback plus re-teaching to develop that skill in the teacher herself.

Cross-check — contrasting the other options:

• Inquiry learning: learners themselves pose questions and investigate to arrive at conclusions — a strategy for how students learn content, not a training procedure for the teacher's own skill.

• Team teaching: two or more already-trained teachers jointly plan and deliver instruction to a combined group — an organisational arrangement for delivering lessons, not a technique for building an individual teacher's skill.

• Discovery learning: learners construct concepts through their own exploration and experimentation — again a student-centred learning strategy, not a teacher-training method.

The method for the acquisition of teaching skill is therefore micro-teaching — the skill-specific, feedback-driven practice cycle described above.