The nurse is reviewing the results of a sweat test taken from a child with cystic fibrosis. Which finding supports the client's diagnosis?

C A sweat potassium concentration greater than 40 mEq/L B A sweat chloride concentration greater than 60 mEq/L A A sweat potassium concentration less than 40 mEq/L D A sweat chloride concentration less than 40 mEq/L