In accordance with Lev Vygotsky's theory, a teacher should :

Correct option is C

According to Lev Vygotsky's theory, a teacher should provide scaffolding to students so that they can achieve their best potential. Vygotsky's theory emphasizes the social context of learning and the importance of more knowledgeable others (such as teachers) in assisting learners to move beyond their current level of development. By providing scaffolding – support, guidance, and encouragement – teachers can help students to reach their Zone of Proximal Development (ZPD), which is the difference between what a learner can do without help and what they can achieve with guidance and encouragement from a skilled partner. This approach enhances learning and skill development, unlike the other options which either discourage collaboration, limit learning tools, or promote unhealthy competition.