Which of the following statements are logically equivalent? A. All aeroplanes are polluting vehicles. B. No polluting vehicles are aeroplanes. C. All non-polluting vehicles are non-aeroplanes. D. No aeroplanes are non-polluting vehicles. Choose the correct answer from the options given below:

Directions: In each of the following questions, three statements are followed by three conclusions numbered I, II, and III. Take the given statements to be true even if they seem to be at variance with commonly known facts. Read all the statements carefully and decide which of the conclusions logically follow. Statements: Only a few books are covers. Some covers are bright. No bright is device. Conclusions: I. Some books are device. II. Some bright are covers. III. Some device are covers.

Directions: In each of the following questions, three statements are followed by three conclusions numbered I, II, and III. Take the given statements to be true even if they seem to be at variance with commonly known facts. Read all the statements carefully and decide which of the conclusions logically follow. Statements: Only a few metal are dust. Some dust are stone. All stone are heat. Conclusions: I. Some dust are heat. II. Some heat are not metal. III. Some metal are stone.