After years of declining populations, there's a bright spot in the world of butterflies. In both the United Kingdom and parts of North America, butterfly numbers are bouncing back. For some species, this population news signifies that 2019 was their best year for growth in more than two decades, according to the journal Butterfly Conservation. Which sentence could be added to the paragraph while maintaining a consistent tone?

Certain butterflies are on the endangered species list.

This is great news for butterflies and the people who love them.

I think butterflies are important to the environment.

If human beings would leave them alone, butterflies would be fine.