A“blitz” is different from a “blitzkrieg” because only a “blitz”

targets civilians.

relies exclusively on air power.

takes place at great speed.

destroys large portions of the country.

B. Relies exclusively on air power

Explanation:

The word blitz is a Germanism derived from the term "Blitzkrieg" - a junction of the German words "Blitz" (lightning or that takes place at great speed) and "Krieg" (war); strategy created by the Nazi army to reverse the losses of the trench clashes.  The "lightning-war" aimed at destroying the enemy's defensive troops as fast as possible, or at least fast enough to not let them organize themselves.

i think it was because of how protected egyptian civilization was was which allowed them to evolve without much outside influence.