Final answer:
The true statement about buoyancy is that it is an upward force that acts in opposition to gravity, allowing objects to float, sink, or remain suspended depending on the balance between this force and the object's weight.
Step-by-step explanation:
The correct statement regarding buoyancy is that it is an upward force exerted by a fluid that opposes the weight of an immersed object. Therefore, among the given options, the true statement is that buoyancy acts in the opposite direction of gravity (C). This is because buoyancy results from the increased pressure with depth in a fluid, which creates a net buoyant force that pushes up against the weight of the submerged object. If the buoyant force is greater than the object's weight, it floats; if less, it sinks; and if equal, the object remains at its current depth.