In which stage do stars spend 90% of their life fusing hydrogen? By Ahmed Akber 🌐 Source Astronomy Knowledge Base ✅ Fact Checked 📊 Difficulty Medium 📅 Last Updated 13 Aug 2026 A. Red Giant B. Main Sequence C. Nebula D. Protostar Check Answer 💡 Explanation: Stars spend the majority of their lifetimes in the stable Main Sequence phase. 📚 Topics: Astronomy Science 🎯 Exams: CSS GEN NTS PMS