Answer is d is correct. All the listed principles—non-refoulement, right to self-determination, and sovereign immunity—are recognized as customary international law, binding on states even without written treaties. Therefore, option (d) is the correct answer.

Answer is c is correct. Section 35 of BNSS requires police officers to record reasons for arrest or non-arrest in writing, ensuring accountability and transparency in the arrest process. Therefore, option (c) is the correct answer.

Answer is b is correct. Section 193 of BNSS stipulates that investigations for offences punishable with less than 10 years of imprisonment must be completed within 60 days, aiming to expedite the criminal justice process. Therefore, option (b) is the correct answer.

Answer is a is correct. According to Article 51 of the UN Charter, a state has the inherent right to self-defence if an armed attack occurs against it. Therefore, option (a) is the correct answer.

Answer is b is correct. Section 304 of the BNS specifically criminalizes mob lynching, treating it as a separate offense to address the growing concern of mob violence. Therefore, option (b) is the correct answer.