A satellite in force-free space sweeps stationary interplanetary dust at a rate of (dm / dt) = α v where m is mass and v is the speed of satellite and a is a constant. The deceleration of the satellite is

• A

  $\frac{2{\mathrm{\alpha v}}^2}{\mathrm{m}}$

• B

  $\frac{{\mathrm{\alpha v}}^2}{\mathrm{m}}$

• C

  $\frac{{\mathrm{\alpha v}}^2}{2\mathrm{m}}$

• D

  ${\mathrm{\alpha v}}^2$