OneDrive (specifically OneDrive for Business in a Microsoft 365 context) is the service designed for individual users to store, sync, and share their personal work files. Each licensed user gets their own OneDrive storage space, which is private by default but allows for sharing with others. It is integrated into the user's Windows profile and Microsoft 365 apps, serving as the primary location for an individual's documents and files, distinct from the collaborative storage provided by other services.

B. SharePoint Online is designed for team and organizational collaboration, providing shared document libraries, intranets, and team sites, not personal storage.

C. Exchange Online is the email, calendaring, and contact management service. While it stores data, its primary function is not general-purpose file storage.

D. Microsoft Teams is a collaboration hub that uses SharePoint for team files and OneDrive for private chat files, but it is not the primary storage service itself.

1. Microsoft Support. (n.d.). What's the difference between OneDrive and SharePoint? Microsoft 365 documentation. Section: "When to use OneDrive vs. SharePoint". Retrieved from https://support.microsoft.com/en-us/office/what-s-the-difference-between-onedrive-and-sharepoint-9005413a-0632-425e-90a7-3e1392b6a87a

2. Microsoft Learn. (2023). SharePoint and OneDrive in Microsoft 365. Enterprise-level documentation. Section: "OneDrive". Retrieved from https://learn.microsoft.com/en-us/sharepoint/sharepoint-onedrive-overview