Read the passage and then answer the question. Pestilence, that old follower of warfare, did not arrive until the very end of [ World War 1] in 1918. For four years medical science staved off any general epidemic; then came a great outbreak of influenza about the world which destroyed many millions of people.
Famine also was staved off for some time. By the beginning of 1918 however most of Europe was in a state of mitigated and regulated famine. The production of food throughout the world had fallen very greatly through the calling off of peasant mankind to the fronts, and the distribution of such food as was produced was impeded by the havoc wrought by the submarine, by the rupture of cutomary routes through the closing of frontiers, and by the disorganization of the transport system of the world...
By the fourth year the whole world was suffering from shortages of clothing and housing and of most of the normal gear of life as well as food. Business and economic life were profoundly disorganized. Everyone was worried and most people were leading lives of ... discomfort
Which of these statements is true?
A) There was a casual relationship between World War 1 and a worldwide outbreak of disease.
B) There was a casual relationship between medical advancements and the influenza outbreak.
C) There was a casual relationship between economic chaos and increased food production
D) There was a casual relationship between submarine warfare and new shipping technology.