Statement coverage is a white-box test technique which focuses on the percentage of executable statements that has been executed by a test suite. This is the best description of statement coverage, as it measures how many statements in the source code have been covered by one or more test cases. Option A is incorrect, as it describes state transition testing, which is a black-box test technique that uses a state table to derive test cases.
Option B is incorrect, as it describes error guessing, which is an experience-based test technique in which test cases are based on the tester's knowledge of past failures. Option D is incorrect, as it describes decision coverage, which is a white-box test technique that covers the decision results which determine the next statement to be executed.
References: , Section 4.2.2