下列各项的烧杯中均盛有稀硫酸。其中铜电极上能产生气泡的是（ ）
A <img width="80" height="138" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163422_5558.jpg" /> B <img width="71" height="105" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163423_7444.jpg" /> C <img width="98" height="104" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163424_6652.jpg" /> D <img width="148" height="138" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163425_8215.jpg" />
