题目

A hobby is any activity a person likes to do in his spare time.So those who get busy in their activity never get bored in their free time.Hobbies vary from person to person.Hobbies are of different kinds.They can be indoors or outdoors.Some are costly and some are cheap.Pursing a particular hobby is a matter of personal choice. My favorite hobby is coin collection.It is also one of the oldest hobbies of the world and is also called hobby of the Kings,as in the old times,it was only done by kings and elite（精英）class of the society.It started for me some years back when my father若函数在内为增函数,则实数的取值范围是( )A. B. C. D.