[单选题]
A uniform electric field, with a magnotnzm*1 sf0.l ie.5/ o5lh1qnm.m3wv ckq -nd :goiw-ytude of 500 V/m, is directed parallel to the +x axi nom:./5vki-dwq.n31ge cm oq- 5lyhws. If the potential at x = 5.0 m is 2500 V, what is the potential at x = 2.0 m?
