18. which process led to the release of large amounts of carbon dioxide at the end of the devonian period? explain

a. the melting of glaciers
b. the breakup of pangaea
c. the volcanic activity
d. the extinction of plant life

C. The volcanic activity

Explanation:

The Devonian period is the period in which the diversification of life exploded. The fish types increased significantly, while the plants started to develop proper roots and grew much larger. Also, in this period we have the formation of the first soils.

As a period it has been relatively cold, and the main reason for that are the plants because they extracted large amounts of carbon dioxide from the atmosphere. By the end of this period though, large volcanic eruptions occurred, and through them, lot of carbon dioxide was released into the atmosphere, warming up the planet for few degrees and changing the climate.

the value of the 4 in the hundreds place is 400 while the value of th e 4 in the tens place is 40

400 is way bigger than 40.