Mr Clark lives at the foot of the mountain.He keeps the forest for a rich farmer there.The only road to the forest is just in front of his house.He can easily see the people who want to go into the forest.Sometimes he has to be on duty at night.When he hears some sound，he has to get up to see if anyone cuts the trees.
One day he bought a strong dog in the town.He loves it very much and often gives some meat or bread to it.And when a strange man walks close to his house，it barks loudly.So he can soon know about it and goes out to find out who it is.
But last week something was wrong with Mr Clarke.He didn’t feel well and couldn’t fall asleep in the evening.He had to go to a hospital in the town.The doctor looked him over and then asked，“Have you got a dog，sir？”
“Yes，I have got one.”
“You have got skin disease，”said the doctor.“I am sure your dog infected（感染）it to you.You can’t come in touch with it any longer.”
When he came out of the hospital，Mr Clarke said to himself，“I will see another doctor.It’s much easier to find a doctor than to buy a good dog!”

The owner of the forest is （）.

A.Mr Clarke
B.a friend of Mr Clarke's
C.a rich farmer
D.the doctor