单选题Question 14 Choose the correct letter, A, B, C or D. Write the correct letter in box 14 on your answer sheet. Which of the following phrases best describes the main aim of the passage ?
A. to analyze the market share distribution of different smart-phone maker
B. to explain the development and functions of smart-phones
C. to depict the current smart-phone patent war
D. to present the regulations and control over the smart-phone market