D Deepak Sahoo 🎓 Tutor II ⭐ 10.83K Points 📊 Computer Q. X.21 is physical level standard for (A) X.25 (B) CSMA/CD (C) ATM networks (D) None of the above 👁️ Show Answer 🔗 Share ⚡Menu ✅ Correct Answer: (A) X.25 You must be Logged in to update hint/solution 💬 Discussion 💬 Comment