Mr. Flowers had tried to ______ to protect his gla

单项选择题

There was once a man called Mr. Flowers, and flowers were his only joy in life. He spent all his free time in one of his four glass-houses and grew flowers of every color, with long and difficult names, for competitions(比赛). He tried to grow a rose of a new color to win the silver cup(银杯) for the Rose of the Year.
Mr. Flowers’ glass-houses were very near to a middle school. Boys of around thirteen of age were often tempted(引诱) to throw a stone or two at one of Mr. Flowers’ glass-houses. So Mr. Flowers did his best to be in or near his glass-houses at the beginning and end of the school day.
But it was not always possible to be on watch at those times. Mr. Flowers had tried in many ways to protect his glass, but nothing that he had done had been useful. He had been to school to report to the headmaster; but this had not done any good. He had tried to drive away the boys that threw stones into his garden; but the boys could run faster than he could, and they laughed at him from far away. He had even picked up all the stones that he could find around his garden, so that the boys would have nothing to throw; but they soon found others.
At last Mr. Flowers had a good idea. He put up a large notice(布告) made of good, strong wood, some meters away from the glass-houses. On it he had written the words: DO NOT THROW STONES AT THIS NOTICE. After this, Mr. Flowers had no further trouble; the boys were much more tempted to throw stones at the notice than at the glass-houses.

Mr. Flowers had tried to ______ to protect his glass.

A. ask the headmaster for help
B. pick up all the stones around his garden
C. do all the above