Question 23: Vietnam has become an attractive tourist destination in ______ Asia. A. Ø (no article) B. the C. a D. an

The correct answer is B. "the". The sentence should read: "Vietnam has become an attractive tourist destination in the Asia." In English, we use "the" before names of geographical areas, rivers, mountain ranges, groups of islands, canals, and oceans. So when we refer to regions such as "the Asia", "the Middle East", "the West", etc., we use "the".