In respect of investigation as provided under section 2(h) of Criminal Procedure Code, which of the following is incorrect

Section 2(h) of the Code of Criminal Procedure (CrPC) defines "investigation" as the process of collection of evidence by a police officer or any person authorized by a Magistrate.

So, both options A and B are correct:
A. Investigation can be conducted by a police officer.
B. Investigation can be conducted by any person authorized by a Magistrate.

Option C is incorrect:
Investigation cannot be conducted by a Magistrate himself. A Magistrate is responsible for judicial functions and decision-making, and the investigation is generally carried out by police officers or persons authorized by a Magistrate.