Word Usage Concept 2

Directions: In the question, there are three / four sentences. Each sentence has pairs of words/phrases that are italicized and highlighted. Select the most appropriate word or phrase to form grammatically and syntactically correct sentences. Then, from the options given, choose the best one.I. The commandant of the 2^nd corpse (A) / corps (B) has put his troops on high alert.
II. The company stands to loose (A) / lose (B) its monopolistic position in the market.
III. The pilot had to take emergency landing and the plain (A) / plane (B) taken to the hangar.
IV. It is our national duty to cast (A)/ caste (B) our vote at the time of national elections.