WW1 experience shows that "A" is the best answer. The British tried a long wide battle line at the Somme and thousands were mown down in minutes by the German machine guns.

Attack columns worked in the 1800s because guns could not fire quickly enough to stop the column. In WW1 artillery, machine guns and massed rifle fire butchered attacking columns.

Spreading crawling men randomly is very slow and increases the risk someone will set off an alarm.

A single file only gave the enemy one target to shoot at - the man at the front - and showed the men who followed the best way across the battlefield