Option 1: Lai Bahadur Shastri - Although Lai Bahadur Shastri served as the Prime Minister of India, he did not have the shortest span in office. He held the position from 1964 until his death in 1966.

Option 2: Chaudhary Charan Singh - The correct answer. Chaudhary Charan Singh had the shortest span in office as the Prime Minister of India. He served as the Prime Minister for only a few months from July 28, 1979, to January 14, 1980.

Option 3: Chandra Shekhar - Chandra Shekhar served as the Prime Minister of India from November 1990 to June 1991. While his tenure was relatively short, it was not the shortest among the options provided.

Option 4: H. D. Deve Gowda - H. D. Deve Gowda served as the Prime Minister of India from June 1996 to April 1997. Although his tenure was brief, it was not the shortest among the options provided.

Therefore, the correct answer is Option 2, Chaudhary Charan Singh, who had the shortest span in office as