Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits blank (21). Tran Dai Nghia (1913-1997) - The Buddha of Guns Professor, Academician Tran Dai Nghia is a (17) ______ scientist of Vietnamese intellectuals. In 1935, the young man Pham Quang Le, his real name, had a scholarship (18) ______ in France. He tried to take 6 college degrees and certificates of the most famous universities of France. Unlike the others, Pham Quang Le had a clear purpose when studying abroad. He studied the science (19) ______ making weapons to serve the country"s independence. The meeting between him and President Ho Chi Minh in Paris in 1946 changed the life of Pham Quang Le. In 1946, under the requirements of the (20) ______, he was assigned as Head of Military Department by Uncle Ho with the (21) ______ for researching, manufacturing weapons for our soldiers to fight the enemy. Uncle Ho said, “This is the good thing, so from now on your name is Tran Dai Nghia...” A: development B: responsibility C: work D: assignment