Critical Reasoning

Using armored vehicles to detonate buried land mines entails an unavoidable risk of injury or fatality, but disarming and removing land mines manually currently entails an even greater such risk to those who remove land mines per mine removed. Therefore, in order to reduce the risk of injury or fatality without decelerating the effort to remove buried land mines, we must increase the use of armored vehicles and disarm fewer land mines by hand.

Which of the following, if true, most seriously undermines the argument above?

A. Manual mine disarmers can be quickly trained in methods that significantly decrease their risk of injury or fatality.
B. Injuries caused by manual disarmament tend to be far more serious than injuries caused by armored vehicle detonations.
C. The delivery of armored vehicles with which to detonate buried land mines can be organized easily by military field operatives.
D. Land mines detonated by armored vehicles destabilize the land surrounding the mine, while land mines that are successfully disarmed manually cause no such damage.
E. Hiring and training those who remove mines by hand is far less costly than is importing heavy armored vehicles to detonate buried land mines.
[spoiler]
OA: A. Source: Knewton[/spoiler].