(B) Dalton was an English chemist who introduced an atomic theory and Rutherford discovered the atomic nucleus.
(C) Einstien was a physicist who developed the theory of relativity and Maharishi Kanad was an Indian philosopher who said that matter is made up of small particles called Parmanu.
(D) Democritus was a Greek philosopher who suggested that matter is made up of tiny individual particles called atoms but Dalton was an English chemist who introduced the first scientific atomic theory.
So the correct answer is (A).