Which treaty allowed the Germans to rebuild Zeppelins after WWI?

The Treaty of Versailles, signed in 1919, formally ended World War I and included numerous stipulations and restrictions aimed at Germany. One notable aspect of this treaty was that it allowed for the rebuilding and use of lighter-than-air craft, including Zeppelins, under specific conditions. Despite the overall punitive nature of the treaty towards Germany, the clauses regarding aviation did not completely prohibit the development of naval and aerial capabilities, which included airships.

The Treaty of Trianon and the Treaty of Saint-Germain were both related to the post-war restructuring of territories and did not specifically address German aviation capabilities. The Treaty of Paris, while associated with various peace settlements, is too general a term in this context to refer specifically to the treaties pertaining to Germany post-WWI. Hence, the Treaty of Versailles is the correct choice as it directly permitted limited rebuilding of Zeppelins amidst its broader provisions.