Concept:One-party system avoids the heavy costs of multi-party electoral competition.
Explanation:In a one-party system, only a single political party is permitted to govern.
Since there are no opposing parties, the country does not spend money on repeated campaigns, election rallies, or political advertisements.
Funds that would have been used for party rivalry are therefore saved and can be used for national development.
This shows that a major advantage of a one-party system is the prevention of economic waste.
While such a system may also produce quick or stable leadership, these are not what it helps to prevent.
Answer:D. economic waste