Which work by Silius Italicus consists of 17 books and centers around the 2nd Punic War?

The work by Silius Italicus that consists of 17 books and centers around the 2nd Punic War is indeed "Punica." This epic poem is notable for its extensive recounting of the conflict between Rome and Carthage, focusing primarily on the military engagements, key figures, and heroism displayed during the war.

Silius Italicus aims to glorify Rome's achievements and depict the valor and struggles of soldiers during this pivotal historical moment. The narrative structure of "Punica" allows for detailed character development and dramatic portrayals of key battles, providing both a historical narrative and a poetic expression of Roman ideals.

The other options listed do not share this specific focus or structure. "Germania," for example, is a work associated with Tacitus that describes the customs and geography of the Germanic tribes, while "Historiae" refers to works by different authors, generally dealing with history, and "Liber Spectaculorum" primarily focuses on entertainment and the spectacles in ancient Rome, rather than military history. Thus, "Punica" stands out as the correct choice within the context of this question.