Camillo Cavour contributed to the unification of Italy primarily through diplomatic and political means, rather than military revolt. He was instrumental in engineering alliances and leading initiatives that facilitated the unification process. Therefore, none of the provided options accurately represent his contributions correctly.
The most relevant statement regarding Cavour’s role would be:
- He organized a popular vote to unite northern and southern Italy.
However, it's important to clarify that while Cavour supported plebiscites in the territories that were annexed, his significant achievements primarily revolved around diplomatic maneuvering and alliances, particularly with France, rather than organizing a popular vote directly.