If the velocity of a body is related to its displacement \( x \) as given by \( v = \sqrt{100+12x} \, \text{m/s} \), then the acceleration of the body is:
\( 0 \)
\( 12 \, \text{m/s}^2 \)
\( 9 \, \text{m/s}^2 \)
\( 6 \, \text{m/s}^2 \)