Final answer:
Ballistic calculations were greatly simplified with the advancement of pre-computed tables, leading to the development of early computers like the ENIAC for faster and more accurate artillery planning.
Step-by-step explanation:
An early military problem that was made much simpler through the development and usage of pre-computed tables was (B) Ballistic calculations. The use of these tables enabled the accurate determination of projectile trajectories, which was essential for effective artillery use. During World War II, the Electronic Numerical Integrator and Computer (ENIAC) was developed to make these ballistic calculations at electronic speed. Previous methods were slower and less precise, leading to inefficiencies and reduced combat effectiveness. Along with the development of radar and efforts to break encryption codes, computing technology profoundly influenced military tactics and decision making.