Heat is primarily transferred in liquids and gases by the method of convection. Convection involves the actual movement of fluid particles, carrying heat with them as they circulate. When a fluid is heated, its particles become less dense and rise, while cooler, denser particles sink. This creates a continuous circulation of the fluid, transferring heat throughout. While conduction can also occur within fluids, it is less efficient compared to convection due to the fluid’s ability to flow. Radiation can also transfer heat in liquids and gases, but it does so primarily in the form of infrared radiation, which is less significant compared to convection. Therefore, while all three methods—conduction, convection, and radiation—can transfer heat in liquids and gases to some extent, convection is the dominant mechanism in this context. The correct answer is [B] Convection.