A thread is tied slightly loose to a wire frame as in figure and the frame is dipped into a soap solution and taken out. The frame is completely covered with the film. When the portion A punctured with a pin, the thread.

• A

  Becomes concave toward A

• B

  Becomes convex towards A

• C

  Remains in the initial position

• D

  Either (a) or (b) depending on the size of A w.r.t. B