Step 1: Principle under Mental Healthcare Act.
The Mental Healthcare Act, 2017 is based on a rights-based approach ensuring dignity, autonomy, and minimal restriction on persons with mental illness.
Step 2: Terminology used in the Act.
The Act uses expressions such as least restrictive alternative, least restrictive environment, and less restrictive option to convey the same underlying principle.
Step 3: Purpose of the principle.
All these terms emphasize providing treatment that satisfies medical needs while imposing minimum restriction on personal liberty and rights.
Step 4: Conclusion.
Therefore, the correct answer is (D) All the above.