[单选题]
Consider a particle ocnay; wl066 xvp6o.g mi;kk20 +slu-d(a fckwbc 2y5if 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. $\frac{1}{2}(mc^2 - m_0 c^2)$
