Y,B,G represent respectively the young's modulus, bulk modulus and rigidity modulus of a body.  If rigidity modulus is twice the bulk modulus, then

Let 

Y,B,G represent respectively the young's modulus, bulk modulus and rigidity modulus of a body

As given in the question,

$\frac{9}{\mathrm{Y}}=\frac{1}{\mathrm{B}}+\frac{3}{\mathrm{G}}$

as G=2B

$\frac{9}{\mathrm{Y}}=\frac{1}{\mathrm{B}}+\frac{3}{2\mathrm{B}}$

$\frac{9}{\mathrm{Y}}=\frac{2+3}{2\mathrm{B}}$

$\frac{Y}{9}=\frac{2B}{5}$

$\mathrm{Y}=\frac{18\mathrm{B}}{5}$

Hence the correct answer is $\frac{18\mathrm{B}}{5}.$