To solve this problem, we are given two scenarios where Sohan travels a total distance of 760 km partly by train and partly by car. We need to find the difference in speeds between the train and the car.

1. In the first scenario, Sohan covers 160 km by train and the remaining 600 km (760 km - 160 km) by car in 8 hours.
2. Let the speed of the train be \(T\) km/h and the speed of the car be \(C\) km/h.
3. The time taken to travel by train is \(\frac{160}{T}\) hours, and by car is \(\frac{600}{C}\) hours. Therefore, we can write the equation: \(\frac{160}{T} + \frac{600}{C} = 8\)
4. In the second scenario, Sohan travels 240 km by train and 520 km by car, taking 12 minutes longer. In terms of hours, this converts to \(\frac{12}{60} = \frac{1}{5}\) hours.
5. The equation for the second scenario is: \(\frac{240}{T} + \frac{520}{C} = 8 + \frac{1}{5}\)
6. Simplifying the second equation, we have: \(\frac{240}{T} + \frac{520}{C} = \frac{41}{5}\)
7. Now, let's solve these two simultaneous equations:
   • Equation 1: \(\frac{160}{T} + \frac{600}{C} = 8\)
   • Equation 2: \(\frac{240}{T} + \frac{520}{C} = \frac{41}{5}\)
8. Multiply the entire first equation by 5 to eliminate the fraction: \(5 \cdot \left(\frac{160}{T}\right) + 5 \cdot \left(\frac{600}{C}\right) = 40\)
9. Equation becomes: \(\frac{800}{T} + \frac{3000}{C} = 40\)
10. Multiply the entire second equation by 5: \(5 \cdot \left(\frac{240}{T}\right) + 5 \cdot \left(\frac{520}{C}\right) = 41\)
11. Equation becomes: \(\frac{1200}{T} + \frac{2600}{C} = 41\)
12. Solving these simplified equations using substitution or elimination method, we derive: \(C - T = 20\)
13. Therefore, the difference in speeds between the car and the train is 20 km/h.

Hence, the correct answer is 20 km/h.