Which one of the following four teaching methodologies followed by four different Science teachers for teaching the topic 'Air Pollution' is most appropriate (CTET Jan 2012)

• A. Dictating the answers to all the questions in the exercise after completing the topic
• B. Showing a documentary film on 'Air Pollution' to the students
• C. Asking the students to collect air samples before and after Diwali, study their quality and tabulate the findings
• D. Asking the students to read the topic from the text book loudly and explaining the meaning of concepts/terms