Which one of the following factors constitutes the best safeguard of liberty in a liberal democracy?

Separation of powers is the best safeguard of liberty because it establishes a system of checks and balances that prevents any single branch of government from exercising absolute power or infringing upon individual rights. While an elected government (Option C) is a prerequisite for democracy, it is not a sufficient safeguard on its own as it can lead to a "tyranny of the majority" without structural restraints. The core concept being tested is constitutionalism, which seeks to limit the powers of the state to protect the freedom of its citizens.