# A bubble of an ideal gas is trapped in a liquid filled in a container. As the bubble moves upwards besides the buoyancy force, the forces acting on it are:

(A) only the force of gravity (B) force of gravity and force due to pressure of liquid (C) force due to gravity and force due to pressure of liquid and viscosity of liquid (D) force of gravity and force due to viscosity of liquid

The bubble is acted upon by force of gravity, force due to viscocity and buoyant force.
The buoyant force is the force which acts due to the pressure of the liquid.
Hence (D) is the correct answer.