HOTSPOT - You are creating an app that uses Event Grid to connect with other services. Your app`s event data will be sent to a serverless function that checks compliance. This function is maintained by your company. You write a new event subscription at the scope of your resource. The event must be invalidated after a specific period of time. You need to configure Event Grid. What should you do? To answer, select the appropriate options in the answer area. NOTE: Each correct selection is worth one point. Hot Area: 

Box 1: SAS tokens - Custom topics use either Shared Access Signature (SAS) or key authentication. Microsoft recommends SAS, but key authentication provides simple programming, and is compatible with many existing webhook publishers. In this case we need the expiration time provided by SAS tokens. Box 2: ValidationCode handshake - Event Grid supports two ways of validating the subscription: ValidationCode handshake (programmatic) and ValidationURL handshake (manual). If you control the source code for your endpoint, this method is recommended. Incorrect Answers: ValidationURL handshake (manual): In certain cases, you can`t access the source code of the endpoint to implement the ValidationCode handshake. For example, if you use a third-party service (like Zapier or IFTTT), you can`t programmatically respond with the validation code. Reference: https://docs.microsoft.com/en-us/azure/event-grid/security-authentication