Answer: The correct answer is-
C. Make it measurable by explaining how far away the target is.
As per the information given in the question, the shooter wants to make improvement in the target shooting accuracy by 20 percent. In order to increase shooting accuracy, first he should measure the distance between target from a set distance.
With the gradual increase of time, he should increase the distance and observe shooting accuracy.
If the shooting accuracy from a longer distance is as accurate as it was from a shorter distance, it will indicate improvement.
Thus, option C) is the right answer.