Which of these equations is not parabolic?

• A. ( rho dot{q} frac{ partial}{ partial x}(k frac{ partial T}{ partial x})+ frac{ partial}{ partial y}(k frac{ partial T}{ partial y})+ frac{ partial}{ partial z}(k frac{ partial T}{ partial z})= rho frac{ partial e}{ partial t} )
• B. ( rho dot{q}+ frac{ partial}{ partial x}(k frac{ partial T}{ partial x})= rho frac{ partial e}{ partial t} )
• C. ( frac{1}{ rho C_v}[ frac{ partial}{ partial x}(k frac{ partial T}{ partial x})+ frac{ partial}{ partial y}(k frac{ partial T}{ partial y})+ frac{ partial}{ partial z}(k frac{ partial T}{ partial z})]= frac{ partial T}{ partial t} )
• D. ( frac{ partial}{ partial x}(k frac{ partial T}{ partial x})+ frac{ partial}{ partial y}(k frac{ partial T}{ partial y})+ frac{ partial}{ partial z}(k frac{ partial T}{ partial z})=0 )