Hint:Dr.B.R.Ambedkar was the main leader in the Freedom Movement for Dalits. He is considered as the father of Indian Constitutions . He is also considered as the chief architect of the Indian Constitution. He belonged to a dalit community present in the Madhya Pradesh.
Complete answer: Let us discuss Dr.B.R.Ambedkar. His birth name was Bhimrao Ramji Ambedkar. He was born in April,14,1891, in Mhow, British India.He was an Indian scholar, economist, jurist, politician and social reformer. Ambedkar was the only untouchable enrolled at Elphinstone High School at his time. He completed this school education and also became the first graduate in his community. He was a Minister of labour in Viceroy's Executive council .He led the dalit moment and campaigned against social discrimination towards the untouchables. He wrote the constitution of India.Depressed class association was established by Dr.B.R.Ambedkar in $August,1930$ . He requested separate electorates for Dalit , the lower caste system. He was appointed as the first Minister of Law and Justice of Independent India with Jawaharlal Nehru as Prime Minister and Rajendra Prasaf as President. He headed the committee which led the constitution drafting. The Government of India awarded the Bharat Ratna posthumously for his efficient nwork on the upliftment of dalit people and drafting the constitution of India.
Hence, the correct answer is option (A).
Note:Several leaders struggled to remove the caste system, in that Dr.B.R.Ambedkar had a major contribution. Their efforts made India to emerge as a nation with Unity in Diversity. India consists of a large number of religions and castes but they are united.