题目

One day I walked down to get to my car, thinking about what I had to accomplish and scolding myself for being late for work, but surprisingly the car was nowhere to be found. This was at 8 a．m. in the morning. I made trips to all the towing places and police stations, all the time thinking that it was towed (拖走)by cops (巡警). By around 10 a．m., the cops decided that it was actually stolen. After filling a report with them. I finally got to work thinking how my day was completely messed up. Later in the day I went to pick up a rental car at Enterprise only to realize that my DNA的双链在解旋时，从氢键连接处断开的碱基对是(    ) A．A与T           B．A与G         C．C与T        D．G与T