[单选题]
The absolute potential at a n)xi gzvo 4/,grbl+) kdistance of 2.0 m from a positive point charge is 1kvrrh a1 8fjcns19*x+sh (k:m00 V. What is the absolute potential 4.0 m away from the same point chkh h8xms +f(:cjar1vs91k r*narge?
A. $25 \; V$
B. $50 \; V$
C. $200 \; V$
D. $400 \; V$