根据以下资料，回答下列各题。 The morning had been a disaster.My tooth was aching,and I’d been in an argument with a friend.Her words still hurt：“The trouble with you is that you won’t put yourself in my place.Can’t you see things from my point of view?”Ishook my head stubbomly—and felt the ache in my tooth.I’d thought I could hold out till my dentist came back from holiday,but the pain was really unbearable.I started calling the dentists in the phone book,but no one coule see me immediatcly.Finally,at about lunchtime,I got lucky. “If you come by right now,”the receptionist said,“the dentist will fit you in .” I lookmy purse and keys and rushed to my car.But suddenly I began to doubt about the dentist.What kind of dentist would be so eager to treat someone at such short notice?Why wasn’t he as busy as the others? In the dentist’s office,I sat down and looked around.I saw nothing but the bare walls and I became even more worried.The assistant noticed my nervousness and placed her warm hand over my ice-cold one. When I tole her my fears,she laughed and said ,“Don’t worry.The dentist is very good.” “How long do I have to wait for him?”I asked impatiently. “Come on ,he is coming.Just lie down and relax.And enjoy the artwork,”the assistant said. “The artwork?”Iwas puzzled. The chair went back,suddenly I smiled.There was a beautiful picture,right where I could enjoy it ：on the ceiling.How considerate the dentist was ！At that moment,I began to understand what my friend meant by her words. What a relief！ Which of the following best describes the author’s feeling that morning?