Why cannot expansion of rights be called mere arbitrariness of courts?

Because it is based on interpretation of constitutional values and changing social needs

The governing concept is constitutional interpretation. Courts do not expand rights simply according to personal preference; they interpret the Constitution, its guarantees, its underlying values and the purpose of protecting dignity and liberty. Social conditions may also change, so a constitutional right can be applied to new forms of harm or exclusion while remaining connected to the constitutional text and principles. This reasoning does not mean that courts have unlimited power: their decisions must be justified, reasoned and open to constitutional scrutiny. Option A is correct because it identifies principled interpretation and changing social needs. Options B, C and D are false or irrelevant and do not explain how constitutional rights are developed.

This is a Class 9 Civics question. Chapter: Democratic Rights. Topic: Right to Constitutional RemediesExpanding scope of rights.