Enough died

The British colonized India from 1858 to 1947. Some British colonists had a hard time adapting. The snakes were particularly troubling. The capital area of Delhi was overrun with venomous cobras. Encountering a cobra is quite frightening. It's even worse getting bit by one. The cobras killed many colonists. Enough died that the British government took action. They paid a bounty for every dead cobra.

A: Enough died that the British government took action.

I wonder if “subject” in A is “1” or “2”.

1. Enough

2. That the British government took action.

If “2” is correct, J would like to know the meaning of “died enough”

That the British government took action died enough.