[单选题]
An electron is held up agmu5f u-t*z*zqzw 0t2x hrhuul2 6g r0-p)(aa qainst the force of gravity by the attraction of a fixed proton some distance abol0r-r)uu(pghh6 aqa 2 ve it. How far above the electron is the proton?
A. $1.5 \; m$
B. $2.3 \; m$
C. $3.7 \; m$
D. $5.1 \; m$
