AMumps
BMeasles
CPolio
DSleeping sickness
Correct Option: 3
Explanation:
Polio
Salk had focussed on developing immunisation in a number of fields. As an associate professor of bacteriology at the University of Pittsburgh School of Medicine, USA, Salk carried out field trials of a "killed-virus" vaccine against polio from 1952 to 1954, which proved safe and effective. In the late 1950s a second type of polio vaccine, known as oral poliovirus vaccine (OPV), was developed by American physician and microbiologist Albert Sabin containing live attenuated (weakened) virus which was given orally. In the mid-20th century hundreds of thousands of children world-wide were struck by the ancient, devastating, frightening and debilitating disease every year; by 2016 the vaccines have all but eradicated it.