[单选题]
The diagram below shows214 q93ozfay tt (sxcc a Daniel cell. Z4 )y52z1p yhby pgk g86i0mdhh: mwsq.inc is more reactive than copper. When the spontaneous rkp 8smq6p b)4h51zyhhymd2. :0ig wgyeaction occurs, which statement about the Daniel cell is correct?
A. The mass of the copper electrode will decrease
B. Electrons flow from the copper electrode to the zinc electrode when the cell is operating
C. The blue colour of the copper (II) sulfate solution will fade over time
D. The zinc electrode is the cathode in this cell