A nurse is caring for a child who was admitted with suspected rheumatic fever. The provider prescribes an anti-streptolysin O (ASO) titer. The parent asks the nurse the purpose of the test. Which of the following responses should the nurse make?

A. The ASO titer does not measure therapeutic levels of aminoglycosides; this response is incorrect. B. The ASO titer is not a direct diagnostic test for rheumatic fever but indicates a recent infection with streptococcal bacteria, which can lead to rheumatic fever. C. The test does not confirm immunity but rather measures antibodies against streptolysin O, indicating recent infection. D. An elevated ASO titer confirms that the child had a recent streptococcal infection, which is important in diagnosing rheumatic fever.