Answer: Duplicity.

Most societies recognize ethical principles such as honesty, fairness (or justice), diligence, and respect for the rights of others. **Duplicity**, which involves deception, is generally in violation of these principles. Therefore, it is least likely to be considered an ethical principle. - **A (Justice)**: Incorrect, as justice is a widely acknowledged ethical principle. - **C (Diligence)**: Incorrect, as diligence is also commonly regarded as an ethical principle.

Author: LeetQuiz Editorial Team