Please answer the following question: Read the following article and select the best answer. Article: The kite was originally called Zhiyuan in North China, and Yaozi in South China. Early in the Five dynasties, a man named Li Ye used to make and fly a kite in the emperor's court. He once attached a whistle made of bamboo to the kite. Sound was let out when the kite was flying. The kite was named after Zheng, a kind of Chinese music instrument. Then it was named Fengzheng in Chinese. The earliest kite in the world was made by Motse, a famous Chinese philosopher, who lived 2,300 years ago, for military purposes. He spent three years making an eagle and managed to fly it. The eagle was later regarded as the first kite in the world. Kite-flying became a recreation probably from the Tang dynasty when the royal family and people of the highest class were addicted to it. It was said that the Emperor Xuanzong in the Tang Dynasty once was interested in a kite named Eight Immortals Crossing the Sea flying in the air. Later, the paper-made kite was invented, which cost less and spread quickly among the common people. As time went on, kites flew to various countries in the world. 'The well-known British scientist, Dr. Needham, once described kites as an important scientific invention which spread to Europe from China in his book, A History of China's Science and Technology. The invention of the kite inspired men's dream of flying and led to the invention of the airplane. Question: What led to the invention of the kite according to the passage? - Wars. - An eagle. - Motse's interest in animals. - Motse's dream of flying.
A:
Wars.