The question is asking for the most suitable definition of `liberty` in the context of a political system or state of affairs.

Option 1 defines liberty as protection against the tyranny of political rulers. While this is one aspect of liberty, it is not comprehensive as it only focuses on the political dimension.

Option 2 sees liberty as the absence of restraint. While this is a part of liberty, it is a somewhat limited definition. Total absence of restraint could also lead to chaos, and is not the essence of liberty in a polity.

Option 3 puts forward that liberty is the opportunity to do whatever one likes. This is definitely a common perception of liberty, but again, this definition is limited. The idea of doing whatever one likes without considering others may lead to anarchy, which goes against the spirit of liberty in a polity.

Option 4, which is the correct answer, conceives liberty as the opportunity to develop oneself fully. This is the most balanced and comprehensive definition among the options, since it incorporates the idea of personal growth, self-actualization, and self-determination while implicitly accepting the need for a certain degree of governance and mutual respect in a community or country.