A mobile application suddenly starts encountering an elevated rate of errors when performing operations that rely on a backend service deployed as a serverless function coupled with an integration point for request handling. Upon inspecting the logs, you observe a pattern of 5XX status codes. Considering that invoking the serverless function through the AWS management console yields successful responses, what is the most probable cause for the errors encountered by the application?
Exhaustion of the integration point's request handling capacity due to service limits being exceeded.
The mobile application is sending incorrectly structured requests causing the service to reject them.
The serverless function is missing execution role permissions required to handle requests.
Path or resource mapping on the integration point is misconfigured, leading to a resource not found situation.