According to the Laws of Manu, one reason for declaring war is:

The correct answer reflects a principle found in the Laws of Manu, a traditional text that outlines dharma (moral and ethical duties) in ancient Hindu society. Specifically, the text emphasizes the importance of social bonds and relationships. A key reason cited for declaring war includes the idea of avenging the injury of a friend or ally, which highlights loyalty, honor, and the societal expectation to protect those within one's community.

In ancient Indian thought, the notion of duty to one's friends and allies played a significant role in maintaining social harmony and ensuring that individuals acted in ways that upheld relationships. This reflects a broader cultural ethos where personal honor and reciprocity were foundational to social interactions, indicating that conflict might be justified when one’s friends or allies are wronged.

The other options, while they can logically connect to motivations for war, do not specifically derive from the Laws of Manu. For instance, fulfilling a divine prophecy or the pursuit of wealth and territorial expansion may have been motivations in other contexts or cultures but are less emphasized in this particular text. The focus remains primarily on interpersonal relationships and loyalty when discussing the justification for war within the framework of the Laws of Manu.