Which of the following is known as 'the medical discovery of 20th century'?

Oral Rehydration Therapy (O), a cheap and effective way to tackle moality from diarrohea Hence, it is 'The medical discovery of the century' composition of Reduced Osmolarity ORS - Na+ 75 mmol /L K+ 20 mmol /L Cl- 65 mmol/L Citrate 10 mmol/L Glucose 75 mmol/L Total 245 mmol/L