Question

read this excerpt from the dark game. another thing that changed very little in the years between the wars was the means of obtaining military intelligence. although the use of photography and the telegraph brought some technological advances, the craft of spying on the enemys army still relied on fieldwork. in the rest of the text, how does the author develop this central idea that spying during the civil war still involved mostly fieldwork? by enhancing the readers understanding of which technological advances were used during fieldwork by changing the readers perceptions about how fieldwork could help the union cause by including more detailed information about who did fieldwork for the union and how it was done by adding complexity to the topic by raising the moral issues involved in fieldwork and other espionage

Explanation:

The central idea is about Civil War spying relying on fieldwork. To develop this, details about who did fieldwork (e.g., spies) and how (e.g., methods like disguises, gathering info on - site) would directly expand on the concept. The first option focuses on tech (not the main focus of the central idea). The second option about Union cause is too narrow. The fourth option about moral issues is off - topic. The third option with details on who and how aligns with developing the central idea of fieldwork being the main means.

Answer:

by including more detailed information about who did fieldwork for the Union and how it was done