Which of the choices below lists the successive stages in coal formation from first step to last?

The five successive stages of coal formation are as follows:

step 1: plants decay

step 2: peat is formed

step 3: peat changes to lignite (soft brown coal made from peat)

step 4: bituminous coal is formed (black and brittle and very polluting)

step 5: anthracite coal is formed (highest amount of carbon and clean burning)