Microbiology Which is true about Widal reaction – A Antibody to H Ag appears first and persists B Antibody to 0 Ag appears first and persists C Antibodies to H & 0 Ag appears simultaneously and persists D None of the above 💡 Explanation Which is true about Widal reaction - ✓ Correct Answer: A. Antibody to H Ag appears first and persists