Looking at the choices, we know that we need a significant answer with error less than the order of 10.
Now, in order to find force here, there is nothing to do with momentum and time here. The only source we can find average force is from work-energy conservation.
The total energy of stone, which is the kinetic energy, is converted to the work done by the average force. Hence, we got the equation

, then

Plugging the values in, we have

The correction is, therefore, (D). 47 of 100 people got the right answer.