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?

"This test will indicate if your child has a therapeutic blood level of an aminoglycoside."

"This test will indicate if your child has rheumatic fever."

"This test will confirm if your child has immunity to streptococcal bacteria."

"This test will confirm if your child had a recent streptococcal infection."