[单选题]
You drop a stone into a deep well and hear the splash 2.5 e9 5jhoa70*c 4tf9oyeq, uvcjs later. How deep wl,caudd7l68mto1e 1 is the well? (Ignore air resistance, and assume the velocity of soltoa6 1 cl7w,dd1 m8ueund is 340 m/s.)
A. $25 \; m$
B. $27 \; m$
C. $29 \; m$
D. $31 \; m$
