Two blocks of mass m and 2m are kept on a smooth horizontal surface. Theya are connected by an ideal spring of force constant k. Initially the spring is unstretched. A constant force is applied to the heavier block in the direction shown in figure. Suppose at time t displacement of smaller block is `x_(1)` then displacement of the heavier block at this moment would be

Options

A. `(x)/(2)`
B. `(Ft^(2))/(6m)+(x)/(3)`
C. `(x)/(3)`
D. `(Ft^(2))/(4m)-(x)/(2)`