An on‑premises MySQL database used by the global sales team has infrequent access and requires minimal downtime. The database administrator wants to migrate it to AWS without choosing a specific instance type because the user base may grow. Which service should a solutions architect recommend?

Amazon Aurora Serverless for MySQL is the best choice because it automatically scales compute capacity based on demand, eliminating the need to choose an instance type and accommodating a growing user base. Its serverless nature also means you only pay for what you use, which is cost-effective for infrequent access, and it offers high availability for minimal downtime. Amazon Aurora MySQL requires manual instance type selection and scaling, which doesn't meet the requirement of not choosing a specific instance type. Amazon Redshift Spectrum is for querying data directly in S3 and is not a relational database migration target. Amazon RDS for MySQL requires you to provision and manage instance types, which goes against the requirement.