Which of these is an example of adversative co-ordinating conjunction?

• A. He didn‚Äö√Ñ√∂‚àö√ë‚àö¬•t raise his hand and he didn‚Äö√Ñ√∂‚àö√ë‚àö¬•t raise his voice.
• B. She was pretty, but she was dumb.
• C. Hurry up, else you will lose.
• D. You must have not studied hard, for the paper was easy.