Which of the following is a main resource for Education Cloud?

A primary resource for Education Cloud is the Power of Us online community. This platform serves as a collaborative space for educators, administrators, and Salesforce users to connect, share best practices, and seek guidance. It fosters a rich environment where members can learn from each other, access resources tailored to the educational sector, and participate in discussions about relevant topics in education.

The community's focus on education means that users can find specific insights and support related to the unique challenges and needs faced within the educational landscape, making it an invaluable asset for those implementing or using Education Cloud solutions.

While the other options listed provide significant resources in general Salesforce usage, they do not specifically cater to the unique needs of the education sector like the Power of Us community does. Salesforce Marketplace and AppExchange are platforms for finding and installing apps, while the Salesforce Developer Network focuses on development and technical resources, which may not directly address the educational needs as effectively as the Power of Us community.