Using the formula P=ρgh, we can know that the density of liquid B is less than that of liquid A;

After the two balls are taken out of the liquid respectively, the liquid pressure in the two containers at the bottom of the container is equal,

It can be seen that the depth of liquid b is greater than that of liquid a,

According to the formula F=PS, the pressure at the bottom of liquid B is high.

∫F = PS =ρGHS =ρVG = mg，

Now, after the metal ball is immersed in the liquid, the pressure of the liquid at the bottom of container A is equal to the pressure of the liquid at the bottom of container B;

Displacement liquid A is more important than displacement liquid B, so the volume of ball A is larger than that of ball B. 。

So choose D.