Lead System Architects must enforce unit testing of code while developing Pega applications.

Comprehensive and Detailed Explanation From Exact Extract:

Unit testing in Pega, as taught in Pega Academy’sTesting Missionand thePega Certified Lead System Architect Study Guide, is critical for validating individual rules and ensuring application quality. Its primary benefit is early detection of functional and coding issues, which reduces defects in later stages.

Option A (Incorrect): Unit testing is not primarily focused on memory allocation issues, which are better addressed by performance tools like PAL or heap analysis. Its focus is functionality, per theUnit Testingmodule.

Option B (Incorrect): While unit testing may indirectly reveal performance issues, its primary purpose is not performance optimization but functional correctness, as noted in theTest Automationguidelines.

Option C (Correct): Unit testing identifies functionality and code issues early, such as logic errors or rule misconfigurations, ensuring high-quality code. This is the most significant benefit, as it prevents defects from propagating, per theUnit Testingsection of Pega Community.

Option D (Incorrect): Unit testing does not identify which test rules are best fit; it executes predefined test cases. The focus is on validating functionality, not selecting test rules, per theTesting Frameworkmodule.