The speed of train in going from Bhopal to Varanasi is 100 kmph while when coming back from Varanasi to Bhopal, its speed is 80 kmph. What is the average speed during the whole journey? (correct to two decimal places

• A. 78.56 kmph
• B. 88.89 kmph
• C. 86.53 kmph
• D. 90.52 kmph