AWS Certified Solutions Architect - Professional (#522)

A company is planning the migration of several lab environments used for software testing. An assortment of custom tooling is used to manage the test runs for each lab. The labs use immutable infrastructure for the software test runs, and the results are stored in a highly available SQL database cluster. Although completely rewriting the custom tooling is out of scope for the migration project, the company would like to optimize workloads during the migration. Which application migration strategy meets this requirement?

Re-host
Re-platform
Re-factor/re-architect
Retire