Exam Certified Platform Developer II topic 1 question 423 discussion

A developer is building a complex commission calculation engine in Apex that is called from an Opportunity trigger. During QA it was reported that the calculations are incorrect.

The developer has representative test data and passing test methods in their developer sandbox.

Which three tools or techniques could the developer use to execute the code and pause it at key lines to visually inspect values of various Apex variables? (Choose three.)