[单选题]
Consider a particle ou86zh h,3ghibm bb0s; esv)dks+b4:ef mass $m$ and rest mass $m_0$. Which of the following is the correct expression for the kinetic energy of such a particle?
A. $\frac{1}{2} m_0 v^2$
B. $\frac{1}{2} m v^2$
C. $m c^2 - m_0 c^2$
D. $\frac{1}{2}(mc^2 - m_0 c^2)$
