def show_vnic(client, resource_group_name, vm_name, nic_name):
    """
    Get the details of a VMware virtual machine's NIC.
    """
    virtual_machine = client.get(resource_group_name, vm_name)
    for nic in virtual_machine.nics:
        if nic.virtual_nic_name == nic_name:
            return nic
    return None