[单选题]
Substance A has a density of xbats02 qk,41g fqbz;)b0teto( dqas-by m4j ,;j7oi$3.0 \; g/cm^{3}$ and substance B has a density of $4.0 \; g/cm^{3}$. In order to obtain equal masses of these two substances, the ratio of the volume of A to the volume of B will be equal to
