Final answer:
b) Constitutional monarchy
The unification of Italy occurred under a constitutional monarchy, with King Victor Emmanuel II and Count Camillo di Cavour playing key roles in its establishment.
Step-by-step explanation:
The unification of Italy occurred under a constitutional monarchy. The process of unification began in the first half of the nineteenth century and was greatly influenced by the rise of nationalism and liberal ideologies. Italy, then a collection of states, saw a movement to consolidate these diverse regions into a single nation-state.
Count Camillo di Cavour, who served the Kingdom of Piedmont-Sardinia, is widely recognized as the architect of Italian unification. Under King Victor Emmanuel II, a constitutional monarchy was established where the king maintained significant power but worked alongside ministers and a limited electorate that was initially comprised only of property-owners. Although Italy was transformed from a patchwork of territories into one unified state, it took many years before the government started to serve the wide interests of the populace.
In this political context, the correct option for the political system under which Italian unification occurred is b) Constitutional monarchy.