This is guaranteed by the stimulus. Keeping every sponsor is necessary for the Ensemble's survival. The Ensemble survived. So every sponsor must have stayed.

We don’t know that the Ensemble got funding from other sources. It may have gotten all of its funding from corporate sponsors.

We can prove that no sponsor withdrew, but that's not the same as proving that funding increased. Every sponsor could have maintained exactly the same level of support, or even decreased their contributions somewhat without fully withdrawing. "No one pulled out" doesn't mean "everyone gave more."

The stimulus says the Ensemble has always been financially dependent on corporate contributions, but "dependent on" doesn't specify a proportion. The group could be dependent on corporate funding even if it accounts for less than half of total income, as long as losing it would force the group to shut down.

The stimulus only tells us about the Green Ensemble's corporate sponsors. We can't generalize from one group's experience to a trend about corporate funding for nonprofit theater groups overall. And as explained in (C), we can't even prove that funding increased for the Green Ensemble itself.