Which of the following statements is true about designing test cases to provide complete coverage...

Complete test coverage of a complex system is generally impossible because the number of possible inputs, states, paths, timing conditions, configurations, user behaviors, and environmental combinations can be extremely large. Even with automated tools, exhaustive testing is usually impractical or mathematically infeasible. Software quality engineering therefore uses risk-based testing, equivalence partitioning, boundary value analysis, decision tables, coverage criteria, inspections, reviews, and statistical methods to obtain reasonable confidence without testing every possible condition. A longer schedule may improve coverage but does not make complete coverage easy. Automation improves repeatability and efficiency, but it cannot eliminate the explosion of possible combinations. Therefore, complete coverage for a complex system is generally impossible regardless of schedule or tooling.

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