What technology had the greatest impact in War Horse the movie?

i think that all of the anmials were real i did a little reasearch on it try go ogle for more detalis

Explanation:

explanation:

a primary sousrce was there already born and a secondary sousce is when a soil that has been use is being use again that a secondary

answer; (d) i believe that the correct answer is americans finally ran out of ammunition;