Concept:Mother tongue is the language a child naturally learns at home. Using it in school helps children express ideas freely and learn better, especially in early years.Explanation:The National Curriculum Framework (NCF 2005) and the three-language formula recommend that mother tongue be the medium of instruction in primary school. Allowing children to speak in their mother tongue encourages participation and builds confidence. Punishing them for not speaking the school language (Option B) or forbidding mother tongue (Option C) damages learning. Telling parents to use only the school language at home (Option D) is unrealistic and unnecessary. Option A respects children's natural expression and is educationally sound.Answer:Option A: They should be allowed to speak in their mother tongue since expression is important.