Answer:
A. Knowing that the attack might reach us in all too short a time, we
immediately began greatly to increase our industrial strength and
our capacity to meet the demands of modern warfare.
Explanation:
The attack is coming quickly so the logical thing to do is to prepare. The other examples are motivational or pathological statements while the first one (A) uses a clear and methodical string of thought to find a solution for the coming attack.
(If a picture type thing helps you: attack coming soon---what do we do?---begin to prepare for the attack immediately.)
The flowers began to blossom, the bees began to buzz, and the cool breeze slid down my neck. I’ve never experienced anything like it, I looked around admiring the new land plot that I was never expecting to experience before !
