A bullock cart covers a distance of 120 km in 15 hours. If it completes half the journey in 3/5 time, then at what speed will the bullock cart have to travel to complete the remaining journey in the remaining time?

• A. 6.4 किमी प्रति घंटा
• B. 6.67 किमी प्रति घंटा
• C. 10 किमी प्रति घंटा
• D. 15 किमी प्रति घंटा