Prove that if two bubbles of radii `r_(1)` and `r_(2)` coalesce isothermally in vacuum then the radius of new bubble will be `r=sqrt(r_(1)^(2)+r_(2)^(2))`

Options

A. `R = (r_(1)+r_(2))//2`
B. `R = r_(1)(r_(1)r_(2) + r_(2))`
C. `R^(2) = r_(1)^(2) + r_(2)^(2)`
D. `R = r_(1)+r_(2)`