The amount of work done in blowing a soap bubble such that its diameter increases from d to D is (T=surface tension of the solution)

Options

A. `4 pi (D^(2) - d^(2) ) T`
B. `8 pi (D - d^(2) ) T`
C. `pi (D^(2) - d^(2) ) T`
D. `2pi (D^(2) - d^(2)) T`

Answer

D