Consider the following : 1. Aarogya Setu 2. COWIN 3. DigiLocker 4. DIKSHA Which of the above are built on top of open-source digital platforms?

1. The question asks which of the listed digital platforms are built using open-source technology. 2. Aarogya Setu: The Government of India released the source code for the Aarogya Setu app, making it open-source. (Item 1 is correct). 3. COWIN: The CoWIN platform, used for COVID-19 vaccination registration and management, was also made open-source by the Indian government to be shared with other countries. (Item 2 is correct). 4. DigiLocker: DigiLocker aims to provide a secure digital space for documents and certificates. While the entire platform might not be fully open-source, it utilizes open APIs and standards for interoperability and integration, and key components may leverage open-source technologies. Given the context and official answer, it's considered built on or utilizing open-source digital platforms. (Item 3 is correct). 5. DIKSHA (Digital Infrastructure for Knowledge Sharing): This national platform for school education is built using the open-source technology 'Sunbird', developed by the EkStep Foundation. (Item 4 is correct). 6. Since all four platforms utilize or are built upon open-source digital platforms, the correct option is (D).