Explanation
The consultant should package the customizations, refresh the sandbox, and reinstall the customization as the first step to avoid any issues when deploying from a sandbox environment that is a different version from the production org. Packaging the customizations means creating an unmanaged package that contains all the components and metadata that are part of the custom solution. Refreshing the sandbox means creating a new copy of the sandbox environment from the production org. Reinstalling the customization means installing the unmanaged package into the refreshed sandbox environment. This step can help avoid any issues that may arise from deploying from a sandbox environment that is a different version from the production org, such as compatibility errors, missing dependencies, or data loss. Manually updating the production org by installing the release update from GitHub, submitting a case to Salesforce Support to update the production org, or deploying the customizations into the production org via change sets are not steps that the consultant should take first to avoid any issues when deploying from a sandbox environment that is a different version from the production org. References:
https://help.salesforce.com/s/articleView?id=sf.packaging_overview.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.data_sandbox_create.htm&type=5
https://trailhead.salesforce.com/en/content/learn/modules/application-lifecycle-and-development-models/te