1 . A wildfire kills most things in its path, but despite the flames and intense temperatures, rarely is everything reduced to ashes -and that plays a key role in a forest's regeneration. Just one year after the fire, the survivors dominate the forest, and grasses replace the burnt ground. Wildflowers are abundant bushes and small trees have started to grow, and Jack Pine returned. So, it's an amazing ecological system of creating new forest life when it appears that all is lost, one that has evolved throughout the ages, where fire has always played a vital role.
What does the underlined word "one" in the last paragraph refer to?
A.A fire. | B.A life | C.A time. | D.A system |