Final answer:
The Social Q&A feature allows users to engage by posting and answering questions to create a collaborative environment for knowledge exchange and promoting social change.
Step-by-step explanation:
The feature that allows end users to post questions and answer other user questions is known as Social Q&A. This kind of platform promotes a collaborative environment where individuals can engage with one another by providing helpful responses to inquiries. Engaging the community through a Social Q&A platform is an effective approach to prompt quality responses that can promote social change. Users can visit a specific section designated for this purpose, where they can either post a new question or view and respond to existing questions. This is visible in the reference code snippet, www (A123) to Visit this section to post or view questions, suggesting an interactive, user-driven platform for knowledge exchange.