Ravi is attempting to cram an empty airtight bottle into a water-filled beaker. As he attempts to lower it even more, he needs to apply:

${\mathrm{F}}_{\mathrm{buoyant}}={\mathrm{\rho }}_{\mathrm{f}}.{\mathrm{V}}_{\mathrm{f}}$

Where ${\mathrm{\rho }}_{\mathrm{f}}$ is the density of the fluid in which the object is submerged, ${\mathrm{V}}_{\mathrm{f}}$  is the gravitational acceleration, and is the volume of the displaced fluid (or the volume of the item immersed inside the fluid).

The buoyancy force of an object submerged in a fluid/liquid is proportional to the volume of the liquid displaced.  

As Ravi lowers the bottle into the water, the amount of displaced water grows, as does the buoyancy force, requiring him to exert additional power. As a result, option A is right.