A thin metal disc of radius r floats on water surface and bends the surface downwards along the perimeter making an angle $\mathrm{\theta }$ with vertical edge of the disc. If the disc  displaces a weight of water W and surface tension of water is T, then the weight of metal disc is

• A

  $2\mathrm{\pi rT}+\mathrm{W}$

• B

  $2\mathrm{\pi rT} \cos \mathrm{\theta } - \mathrm{W}$

• C

  $2\mathrm{\pi r} \mathrm{T} \cos \mathrm{\theta } + \mathrm{W}$

• D

  $W - 2\mathrm{\pi rT} \cos \mathrm{\theta }$