V Vinay 🎓 Mover ⭐ 28.75K Points 📊 C++ Q. Which of the following is used to prevent multiple inclusions of a header file? (A) #define (B) #ifndef (C) #include (D) #pragma 👁️ Show Answer 💬 Discuss 🔗 Share ⚡Menu ✅ Correct Answer: (B) #ifndef Explanation: The '#ifndef' directive is used to prevent multiple inclusions of a header file.