hello i need help in solving this

Q)If the speed of a vehicle increases by 2 m/s,its kinetic energy is doubled,then original speed of the vehicle is

a)(sqrt of 2 )+1 m/s

b)2(sqrt of 2 -1)m/s

c)2(sqrt of 2 + 1 )m/s

d)sqrt of 2 (sqrt of 2 + 1)m/s

sqrt is square root of

please help me out

Thnx in advance