As can be seen from the figure, the densitometer floats in liquid A and liquid B, and the gravity of the same densitometer remains unchanged, so the buoyancy of the densitometer in the two liquids is equal;

Because the volume of liquid discharged by the densimeter in A is large, the volume of liquid discharged in B is also large, so according to the discharge of F-float =ρgV, it can be known that the density of liquid A is smaller than that of liquid B;

According to p=ρgh, when H is the same, the pressure in liquid A is less than that in liquid B. 。

So choose C.