The differential equation of all parabolas whose axes are parallel to y-axis is

• A.                 \[\frac{{{d}^{3}}y}{d{{x}^{3}}}=0\]        
• B.                 \[\frac{{{d}^{2}}x}{d{{y}^{2}}}=c\]
• C.                 \[\frac{{{d}^{3}}y}{d{{x}^{3}}}+\frac{{{d}^{2}}x}{d{{y}^{2}}}=0\]         
• D.                 \[\frac{{{d}^{2}}y}{d{{x}^{2}}}+2\frac{dy}{dx}=c\]