[单选题]
A point charge is moved betw34d 5mpx6gywyss1wrc6jt 8-t een two parallel plates separated byp0i9 b qhk4q mri5r4,)sk8,dm/ oe7 qgg-cson a distance of 5cm. The)b4i ic qg/05h4p9gnrqs m 8d,r-mskk7e oqo, potential difference between the points is 50V.
What is the average electric field E?
A. 1000$NC^{−1}$
B. 250$NC^{−1}$
C. 10$NC^{−1}$
D. 2.5$NC^{−1}$