Which of the following statements are "testing general principles"?
I. Exhaustive testing is impossible
II. The defects found during the pre-release tests, or the operational failures, are uniformly distributed across the system’s software modules
III. Testing can show the presence of defects, but cannot demonstrate their absence
IV. Testing is context-independent
A. I, III
B. I, II
C. I, IV
D. II, III