In the theory of relativity, the mass of a particle with velocity v is [tex]m = \frac{m_0}{\sqrt{1 - v^2/c^2}}[/tex], where m₀ is the mass of the particle at rest and c is the speed of light. What happens as v → c⁻?
A. m → m₀
B. m → 1
C. m → 0
D. m → m⁻