Concept:A good language textbook must be visually engaging and student-friendly to support effective learning.Explanation:A textbook is a teaching-learning tool. Key features include attractive fonts and illustrations that make the book visually appealing and easy to read. Learner-friendly content means the material is clear, well-organised, relevant, and appropriate for the students’ level. These aspects help students understand and retain language better. Options like interesting stories, extracts, or grammar exercises are less essential for the overall quality of a textbook.Answer:The correct option is B: attractive fonts, illustrations and learner-friendly content.