The correct answer is option 3 - Battle of Wagram. The Treaty of Schonbrunn was signed in 1809 after the Battle of Wagram.

To understand why this is the correct answer, let`s analyze the other options:

- Option 1, Battle of Austerlitz: This battle took place in 1805 and led to the Treaty of Pressburg, not the Treaty of Schonbrunn. Therefore, it is not the correct answer.

- Option 2, Battle of Tilsit: This battle took place in 1807, and although it resulted in the Treaty of Tilsit, it is not related to the Treaty of Schonbrunn. Hence, it is not the correct answer.

- Option 4, Battle of Lisbon: This battle was part of the Peninsular War and occurred in 1810, after the Treaty of Schonbrunn was already signed. Therefore, it cannot be the correct answer.

Thus, it becomes clear that the Treaty of Schonbrunn was signed after the Battle of Wagram, making option 3 the correct answer.