Probable grammar mistake: "State that can trigger updates when changed are considered reactive"

[amire80]

The sentence "State that can trigger updates when changed are considered reactive." appears on https://vuejs.org/tutorial/#step-2

It looks grammatically wrong. It should probably be "A state that can trigger updates when changed is considered reactive." or maybe "States that can trigger updates when changed are considered reactive."

[ijklim]

Agree, I vote for "States that can trigger updates when changed are considered reactive.".