具有吗啡受体纯拮抗作用的镇痛药（）.

A．纳洛酮 

B．布托啡诺 

C．盐酸布桂嗪 

D．磷酸可待因 

E．苯噻啶

Losing a job or not being able to find one almost always brings unwelcome changes. If you’ve lost a job, the first feeling is often one of shock. On top of the loss of income, many people find the whole routine of their life is shattered, their contact with other people reduced, their ambitions halted and their identity as a worker removed.
There may be good feelings too—it’s nice to be able to lie in bed in the morning, to spend more time with children, or to have more time to think—a better job may be just around the corner. But, unless a better job does turn up, chances are the days start getting longer and the time becomes harder to fill. Many people pass through periods of difficulty in sleeping and eating. They feel irritable and depressed, often isolated and lonely.
Despite all these problems, unemployment can be a chance for a fresh start. You can discover that it provides an opportunity to sort out or rethink what you want from life and how best you can get it. You can use the time to plan how to find a new job, learn a new skill, develop your hobbies, see if you can run your own business, do some voluntary work in your community or meet new people. It’s up to you.

The sentence "it’s up to you" means "you are the person who ______. "

A．makes the decision

B．is responsible

C．has the right

D．is confident