The formation of volcanoes takes thousands of years. Volcanoes are formed when magma within the earth pushes up to the surface and erupts out. Once magma is outside the volcano, it is called lava. Erupted lava that has cooled helps to form the shape of the volcano. The cone-shaped volcano may come to many people’s mind when they think of volcanoes, but there are a variety of types of volcanoes. The shapes of these volcanoes typically vary based on the history of volcanic activity, including whether the lava is fast moving or slow moving. A volcano has several channels of magma under it. All these channels come together to form a single stream flowing up through the cone of the volcano. Lava cools and slows as it runs down the side. Eventually, the lava cools completely and becomes a part of the volcano. The accumulation of the cooled lava causes the volcano to grow in size. Volcanoes produce different types of rocks. Lava forms igneous rocks like basalt or pumice. If lava cools very quickly, it can form into glossy rocks like obsidian. Not all magma makes it out of the volcano. Some of it can cool and harden underground to form rocks like granite or diorite. Volcanoes don't always shoot fireballs and flaming rocks into the sky. Some don't do anything at all. Some volcanoes are labeled as dormant or extinct, although these labels may mean different things to different experts. Volcanoes that have not erupted in 10,000 years are considered dormant volcanoes by some experts. This happens when the magma below cannot reach the top because there is not enough pressure or heat to push the magma to the surface. Instead, it retracts back into the earth into underground channels. Eventually, it will cool and harden, pushing the magma back down into the earth. The pressure and heat may increase again, causing the magma to rise and the volcano to erupt. Dormant volcanoes are often unpredictable. No one truly knows when or even if a dormant volcano will erupt again. A volcano could be considered extinct if it remains inactive and there are no signs of activity. Kadovar is a volcanic island in Papua New Guinea. This giant volcano had slept for over three hundred years. Its eruption in January of 2018 came as a surprise to many people. Hundreds had to be evacuated immediately. There were some warning signs of a pending eruption that had been monitored for the last forty years, though. In 1976, temperatures within the volcano rose for some time. And in 2015, the earth within was trembling from seismic unrest. Despite these warning signs, the explosion caught almost everyone off guard. After the eruption, Kadovar is said to live again. Based on the passage, what conclusion can be made about dormant and extinct volcanoes?

Dormant volcanoes are inactive and will never erupt again.
Dormant volcanoes are inactive and will never erupt again.

There is no official criteria for labeling volcanoes as dormant or extinct.

Extinct volcanoes are volcanoes that have been dormant for 10,000 years.

Volcanoes are labeled as dormant because they have been active for many years.