Concept:A political system that permits only one state ideology enforces a single official doctrine and rejects political pluralism.
Explanation:In a socialist state, the government centrally controls the means of production and distribution of goods.
All state institutions must follow socialist principles as the only approved ideology.
Other political ideologies are not officially tolerated.
Opposing views are often suppressed to maintain the ruling ideology.
Hence, socialism is the system that allows only one ideology for the state.
Aristocracy, communalism, and capitalism generally allow a diversity of political views.
Answer:Option A: socialism.