How should a developer add a dataLayer object to the Cart-Show controller route while ensuring it can be removed without code changes?

To ensure proper implementation of the dataLayer object in the Cart-Show controller route while maintaining the ability to remove it later without requiring additional code changes, placing the client cartridge on the left side of the LINK cartridge is crucial. This positioning ensures that any modifications made in the client cartridge take precedence over the base functionality provided by the LINK cartridge.

By replacing the Cart-Show controller route and placing the client cartridge on the left, a developer can effectively customize the functionality for the Cart-Show view without directly modifying the behavior of the LINK cartridge. This strategy enables the developer to manage changes in a modular way, allowing for easy removal or alteration of the dataLayer integration simply by altering the client cartridge without touching the underlying framework—keeping the core code intact and reducing risks of unintended side effects from direct modifications.

The other options lack this critical aspect of modularity and maintainability. For instance, simply replacing the viewData variable or appending to it without managing the cartridge order could lead to complications when changes are required or when maintaining compatibility with framework updates.