Which of the following fallacies involves defective induction?

The argument from ignorance is the fallacy of defective induction here.

Fallacies of defective induction fail because the premises, though relevant, give far too weak support for the conclusion.

In the argument from ignorance the only ground offered is that a claim has not been proved otherwise.

Such absence of contrary proof carries no real inductive weight toward the conclusion.

Reasoning from so weak an inductive base is exactly what places this among the fallacies of defective induction.