What Is Thought to Be the Correct Sequence of the Following

Multiple Choice

What is thought to be the correct sequence of the following events during the Carboniferous period?
1) Vascular plants become more prevalent.
2) Megaphylls with large surface areas become more prevalent.
3) Atmospheric CO₂ levels decline dramatically.
4) Global cooling occurs,leading to widespread glaciations.

A) 1,2 ,3,4
B) 2,1,3,4
C) 2,1,4,3
D) 1,2,4,3
E) 3,4,1,2