Answer:
C. to highlight that starvation has long been used as a tactic during wars
Step-by-step explanation:
The correct option is C to highlight that starvation has long been used as a tactic during wars. By including information about soldiers being starved during the U.S. Civil War, the author is emphasizing that the use of hunger as a tool of war is not a new phenomenon, but has a long history. This information serves to make the argument that hunger and war are inextricably linked and that the issue of hunger in times of conflict is a longstanding problem that needs to be addressed.