A.I. Explanation:

Option 1: "Chief Head of the event."

Explanation: The text does not mention a 'Chief Head of the event' as a judge. Instead, it specifically refers to the 'chief coordinator of that place' as the person involved in the exhibition. Therefore, this option is not supported by the text.

Option 2: "Chief coordinator of the city."

Explanation: The text states that the exhibition was inaugurated by the 'chief coordinator of that place,' indicating that this individual played a significant role in the event. The use of 'chief coordinator' aligns with the context of judging the best innovation and experiment, making this option the correct answer.

Option 3: "Concerned authorities of the event."

Explanation: While the text mentions 'concerned authorities' displaying their innovations, it does not specify that they were responsible for judging. This option lacks direct support from the text regarding the judging role.

Option 4: "People related to the field."

Explanation: The text refers to 'people related to the field' as attendees who would get encouragement to participate in future exhibitions, but it does not indicate that they judged the innovations. Thus, this option is not correct.