Comprehensive and Detailed Explanation From Exact Extract:

FromCTFL-AT Syllabus v4.0, Section 4.3Test Automation and Continuous Integration, it states:

"Automated tests help detect regression defects quickly and can be run frequently during development, thus reducing regression risk."

So,Option Dis correct —test automation supports regression testingwithin iterations, making it an essential Agile practice.

Option Ais false —automated unit tests are designed to be fastand are ideally run with every check-in.

Option Bis incorrect — more code changesincrease, not reduce, regression risk.

Option Cis incorrect —technical debt can still existwith automation if the automation is poorly designed or not maintained.