If the change in the value of ?g? at a height h above the surface of the earth is the same as at a depth x below it, then (both x and h being much smaller than the radius of the earth) [NCERT 1983; BHU 2002]

• A.    \[x=h\]
• B.    \[x=2h\]
• C.    \[x=\frac{h}{2}\]       
• D.    \[x={{h}^{2}}\]