The correct answer is A. mass of liquid displaced.
Buoyancy is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. All objects experience two forces when they are in a fluid: gravity and buoyancy. Gravity pulls the object down, while buoyancy pushes the object up. If the object is more dense than the fluid, then gravity will be stronger than buoyancy and the object will sink. If the object is less dense than the fluid, then buoyancy will be stronger than gravity and the object will float.
The amount of buoyancy an object experiences is equal to the weight of the fluid it displaces. This means that the more mass of liquid an object displaces, the more buoyant it will be.
The other options are incorrect because they do not affect buoyancy. Viscosity is a measure of how thick a fluid is. Pressure is a measure of how much force is exerted on a surface per unit area. Depth of immersion is the distance an object is submerged in a fluid. None of these factors affect the amount of mass of liquid an object displaces, and therefore they do not affect buoyancy.