Question

which of these statements is true?
a. there was a causal relationship between submarine warfare and medical advancements.
b. there was a causal relationship between influenza outbreaks and the closing of frontiers.
c. there was a causal relationship between world war i and an international food shortage.
d. there was a causal relationship between economic chaos and improved shipping technology.

Explanation:

• Option A: There is no direct causal link between submarine warfare and medical advancements. Submarine warfare is mainly about naval combat, while medical advancements have their own independent research and development trajectories.
• Option B: Influenza outbreaks did not cause the closing of frontiers. Frontiers are closed due to various geopolitical, economic, or security - related reasons, not influenza outbreaks.
• Option C: World War I led to a large - scale mobilization of resources. A significant portion of agricultural labor was conscripted into the military, and resources were diverted to the war effort (such as for weapons production, feeding the military). This disrupted agricultural production and distribution, leading to an international food shortage. So, there is a causal relationship.
• Option D: Economic chaos is more likely to be a result of factors like over - speculation, mismanagement, or external shocks (such as wars), rather than being caused by improved shipping technology. Improved shipping technology is more likely to facilitate economic activities (such as trade) rather than cause chaos.

Answer:

C. There was a causal relationship between World War I and an international food shortage.