How is BPDU Guard configured globally on all access ports?

The correct configuration for enabling BPDU Guard globally on all access ports is through the command that specifies the default setting for BPDU Guard in conjunction with PortFast. By using the command that includes "default," it allows the BPDU Guard feature to be activated automatically on all access ports where PortFast is enabled. This is particularly important in a network to prevent loops caused by unexpected Bridge Protocol Data Units (BPDUs) being received on ports that should not participate in the spanning tree.

When BPDU Guard is enabled globally, it ensures that any access port configured for PortFast will transition to an error-disabled state if it receives a BPDU. This is a protective mechanism that helps maintain the stability of the network by preventing possible loops or topology changes that could disrupt the network operation.

The other options focus on either enabling BPDU Guard without the global default application or do not correctly relate to configuring it for all access ports. By using the command that includes "default," administrators ensure consistency across the network without needing to individually configure each access port.