Which command should Dave execute to ensure his deployment won't fail?

The command that Dave should execute to ensure his deployment won't fail is the one that focuses on validating the work done in Copado before submitting it for deployment. The command "sfdx copado:work:validate" is specifically designed to perform validation on the work being submitted to ensure that there are no conflicts or issues that would cause the deployment to fail.

When using this command, Dave will initiate a validation process that checks whether his changes are compatible with the production environment and whether they meet the deployment criteria. This step is crucial in the Continuous Integration/Continuous Deployment (CI/CD) process, as it reduces the risk of deployment errors by catching issues early.

While there may be other commands that perform related functions, such as deploying a check or submitting work for review, the specific focus on validation makes the "sfdx copado:work:validate" command the most appropriate choice to ensure a successful deployment.