Concept:
The Bharat Ratna is India's highest civilian award, and while it is usually given to living individuals, it can also be conferred posthumously.
Explanation:
Lal Bahadur Shastri, India's second Prime Minister, died suddenly in Tashkent in January 1966 shortly after signing the Tashkent Declaration. Later that year, the government conferred the Bharat Ratna on him, making him the first person to receive the award after death. M.G. Ramachandran received the honour in 1988, also posthumously, but well after Shastri. B.R. Ambedkar received it in 1990, again posthumously, decades after his death in 1956. K. Kamaraj was honoured posthumously in 1976. All three came after Shastri's 1966 award.
Final Answer:
Lal Bahadur Shastri was the first posthumous recipient of the Bharat Ratna, so option D is correct.