The correct answer is: Master Tara Singh.
Master Tara Singh was a Sikh leader who was the president of the Shiromani Akali Dal from 1923 to 1967. He was a strong advocate for a Punjabi state and was involved in several protests and agitations for this cause. In 1965, he announced a 15-day hunger strike to demand a Punjabi state. However, he had to postpone his fast due to the outbreak of the Indo-Pakistani War.
Saint Fateh Singh was a Sikh saint who was also a strong advocate for a Punjabi state. He was involved in several protests and agitations for this cause. However, he did not announce a hunger strike in 1965.
Devi Lal was a politician who was the Chief Minister of Haryana from 1977 to 1980. He was not involved in the agitation for a Punjabi state.
Pratap Singh Kairo was a politician who was the Chief Minister of Punjab from 1964 to 1966. He was not involved in the agitation for a Punjabi state.