निम्नलिखित में से कौन-सा द्वितीयक स्रोत का एक उदाहरण है?

For undertaking a project on the 'Freedom Struggle' at the middle school level, which of the following data collection methods may be least essential or appropriate?

While teaching history, a 'genealogy chart' is used to: A. Represent the growth and development of an empire or a dynasty. B. Show sequence and functional relationships. C. Provide a chronological framework. D. Develop a sense of space in learners. Choose the correct option: