[单选题]
An object slides down a frictionless incline3o0dj)t:mx5aq c,ct o d plane. At the bottom, it has a )-c5p 8ovtbpav *.6kq vq7i hbspeed of 9.80 m/s qvqvoa-vt b6 8bpk5*.ci)ph7. What is the vertical height of the plane?
A. $19.6 \; m$
B. $9.80 \; m$
C. $4.90 \; m$
D. $2.45 \; m$
