The best safeguard of liberty in a liberal democracy is option 4: Separation of powers.

In a liberal democracy, the government is structured to ensure that no one branch of government becomes too powerful. The separation of powers is an essential feature of liberal democracies and helps to prevent any one branch of government from infringing on the liberties of citizens. This separation divides the government into three branches: the legislative branch, the executive branch, and the judicial branch. Each branch has its own distinct responsibilities and powers, and no branch is above the law.

The separation of powers ensures that the government is accountable to the people, and that the rights and freedoms of citizens are protected. It provides a system of checks and balances that prevents abuses of power and ensures that no one branch becomes too powerful. In contrast, centralization of powers can lead to authoritarianism, where the government has unchecked power over the lives of citizens.

While a committed judiciary and elected government are important factors in safeguarding liberty, they are not sufficient on their own. A committed judiciary can help to protect individual rights, but it cannot act as a substitute for the separation of powers. Similarly, while elected governments are essential in liberal democracies, they too require the checks and balances provided by the separation of powers to prevent abuses of power.