The work done by a boy in making a soap bubble of diameter $1.4 \mathrm{~cm}$ by blowing, if the surface tension of soap solution is $0.03 \mathrm{~N} / \mathrm{m}$, is :
(a) $3 \times 10^{-5} \mathrm{~J}$
(b) $3.696 \times 10^{-5} \mathrm{~J}$
(c) $2 \times 10^{-5} \mathrm{~J}$
(d) $4.2 \times 10^{-5} \mathrm{~J}$