Which of the following hardware devices prevents broadcasts from crossing over subnets?

A bridge operates at Layer 2 and forwards broadcasts across all connected segments, it does not block broadcasts between subnets.

A hub is a Layer 1 device that repeats all signals to every port, including broadcasts, with no filtering capability whatsoever.

A modem modulates and demodulates signals for WAN connectivity and has no broadcast filtering or subnet segmentation function.

A router operates at the Network layer (Layer 3) of the OSI model and forwards packets based on IP addresses. Routers do not forward Layer 2 broadcast frames between interfaces, effectively containing broadcast traffic within each subnet and separating broadcast domains.