A. Test Execution Time is not critical in agile as there are fewer tests written, and they are designed as checklists or high-level tests which reduces the time it takes to execute them

B. Unit testing automation is the most critical test automation needed in agile and covers most of the testing challenges in agile quality of code and gives good test coverage

C. Test deployment time is one of the challenges of agile testing, as deploying slow is not possible in short iterations

D. Resource's availability is a challenge in automating tests in agile settings, as they are needed to create, maintain, and execute the test suite