Final answer:
Option B, which provides both the author's last name and the title of the work in the citation, is the correct citation format for the information given. World War I saw massive casualties, with battles such as Verdun and Somme accounting for a significant portion of the total military and civilian deaths.
Step-by-step explanation:
When discussing the correct citation format for the information on the number of deaths from a battle in World War I, the more comprehensive citation is usually preferred. Thus, option B, 'On page 26, the author states that the number of deaths from that battle was never officially determined (Sullivan, "The Great War").' is the correct one, as it includes both the author's last name and the title of the work, providing better context for the reference.
Investigating the historic scale of casualties in World War I, we find staggering numbers that illustrate the immense human cost of the conflict. For example, the Battle of Verdun led to approximately 970,000 total casualties without resulting in significant territorial gains for any side.
Similarly, the Battle of the Somme was marked by an astounding death toll, with the British suffering 420,000 casualties alone. Moreover, it's crucial to acknowledge the overall losses throughout the war, totaling between 16 and 19 million military personnel and 7 to 8 million civilians, not including the consequent influenza pandemic.