Which of the following is not an example of primary succession?

New volcanic island forms

Tornado devastates a forest

Lava flow decimates any plant life in it's way

Glacial outwash deposit

Tornado devastates a forest is not an example of primary succession

Explanation:

Tornado devastation of a forest is an example of secondary succession and not primary succession. Secondary succession occurs due to secondarily initiated processes like fires, tornados, etc. It occurs in already previously vegetated areas. Forest being an example of a previously vegetated area, this is an example of a secondary succession. All the other options given are primary succession that happens on not vegetated areas. For example, new volcanic islands that are formed or the vegetation that grows as a result of the retreat of glaciers, etc.