For an Ethernet frame to be valid, how must its size compare to the minimum frame size?

An Ethernet frame must be at least 64 bytes in size to be considered valid. This minimum frame size is crucial for several reasons.

First, the 64-byte minimum helps ensure that the frame is large enough to allow the sending device to detect collisions on the network. Ethernet operates on a principle known as CSMA/CD (Carrier Sense Multiple Access with Collision Detection), where devices sense the network before transmitting. If the frame were too small, it might be transmitted in a time interval that doesn't allow for the detection of a collision, rendering the transmission unreliable.

Second, the structure of an Ethernet frame is defined to ensure proper processing by network devices. A valid Ethernet frame comprises a header, a payload, and a trailer, and the minimum size ensures that these components can be adequately accommodated. This standard size also helps with interoperability among different network devices and manufacturers.

Thus, for an Ethernet frame to meet the requirements of the framing standards and to function correctly in a network environment, it must be equal to or exceed 64 bytes, making that answer the correct choice.