The options for integrating cloud storage and synchronization features into a desktop application primarily include using cloud storage APIs and software development kits (SDKs) provided by popular cloud service providers such as Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform. These APIs and SDKs allow developers to leverage the storage and synchronization capabilities of the cloud provider in their desktop application. Additionally, platforms like Dropbox and Box offer their own APIs for integration. This integration involves authentication and authorization through OAuth or API keys, along with the use of libraries or frameworks for making API requests and managing synchronization. By integrating cloud storage and synchronization, desktop applications can easily store, retrieve, and synchronize files and data across multiple devices, providing a seamless user experience.