A common tangent to the circle x^{2}+y^{2}=16 and the ellipse {x^{2}}/{49}+ {y^{2}}/{4}=1 is

Correct Answer is : y=2x√11+4√1511

y= {2 x}/\sqrt{11}+ {4 \sqrt{14}/\sqrt{11}

y= {2 x}/\sqrt{11}+ {4 \sqrt{15}/{ {11}}