The correct answer is (a) Judicial Magistrate.
A Judicial Magistrate is a judicial officer who has the power to take cognizance of offences under the Code of Criminal Procedure, 1973. The power to take cognizance of an offence means the power to initiate criminal proceedings against a person.
A Judicial Magistrate can take cognizance of an offence on the basis of a complaint, a police report, or on his/her own knowledge. A complaint is a statement made by a person to a Magistrate alleging that another person has committed an offence. A police report is a report made by the police to a Magistrate stating that they have investigated an offence and that they believe that a person has committed the offence.
A Judicial Magistrate can also take cognizance of an offence on his/her own knowledge if he/she is satisfied that there is sufficient ground for proceeding against a person for an offence.
The power to take cognizance of an offence is a very important power. It is the power that starts the criminal justice process. Once a Judicial Magistrate has taken cognizance of an offence, the accused person is then liable to be arrested and prosecuted.
The other options are incorrect because:
(b) A Session Judge is a judicial officer who has the power to try cases of serious offences.
(c) The High Court is a court of appeal. It has the power to hear appeals against the orders of lower courts.
(d) A District Magistrate is an administrative officer who has the power to deal with a variety of administrative matters.