Answer: Option D
External radius = 3 cm
Internal radius = (3 - 0.5) cm = 2.5 cm
Volume of the metal :
$$\eqalign{
& = \left[ {\frac{4}{3} \times \frac{{22}}{7} \times \left\{ {{{\left( 3 \right)}^3} - {{\left( {2.5} \right)}^3}} \right\}} \right]{\text{ c}}{{\text{m}}^3} \cr
& = \left( {\frac{4}{3} \times \frac{{22}}{7} \times \frac{{91}}{8}} \right){\text{ c}}{{\text{m}}^3} \cr
& = \left( {\frac{{143}}{3}} \right){\text{ c}}{{\text{m}}^3} \cr
& = 47\frac{2}{3}{\text{ c}}{{\text{m}}^3} \cr} $$