The speed of light in a vacuum is approximately: A 3 × 10⁶ m/s B 3 × 10⁸ m/s C 3 × 10¹⁰ m/s D 3 × 10⁴ m/s ✓ Correct Answer: Option B The speed of light in vacuum is approximately 3 × 10⁸ m/s (299,792,458 m/s exactly). Practice AP Exam Prep Quizzes → Browse All Questions Study Flashcards