Introducing inhomogeneity to your network for the sake of robustness would have which of the
high costs in terms of training and maintenance.
None of the choices.
An oft-cited cause of vulnerability of networks is homogeneity or software monoculture. In particular,
Microsoft Windows has such a large share of the market that concentrating on it will enable a
cracker to subvert a large number of systems. Introducing inhomogeneity purely for the sake of
robustness would however bring high costs in terms of training and maintenance.