Which solution will meet these requirements with the LEAST ongoing operational overhead?

Explanations:

Amazon Connect provides a fully managed call center service that eliminates the need for on-premises hardware, ensuring improved reliability. Amazon Pinpoint allows for sending interactive surveys via text, which aligns with the company’s requirement for a two-way experience survey. This solution minimizes operational overhead by utilizing managed services.

While Amazon Connect is a suitable choice for replacing the old call center hardware, using Amazon Simple Notification Service (SNS) for sending surveys does not provide the interactive two-way experience required by the company. SNS is better suited for one-way notifications rather than interactive communications.

Migrating the call center software to Amazon EC2 instances in an Auto Scaling group requires more operational management, such as instance provisioning, scaling, and maintenance. This approach does not significantly reduce operational overhead compared to the current on-premises setup. Additionally, it does not specifically address the survey requirement.

Amazon Pinpoint is primarily a communication service that facilitates sending messages but does not function as a call center solution. Replacing the call center hardware with only Pinpoint would not satisfy the requirement for managing incoming calls and customer interactions, thus failing to meet the complete needs of the customer service center.