Why Did Railroad Companies and Other Businesses Form "Pools" During

Why did railroad companies and other businesses form "pools" during the American Gilded Age?

A) They wanted to cut each other out from the market.
B) They hoped to escape the chaos of market forces by fixing prices with their competitors.
C) They hoped to gather enough capital in a pool in order to buy out their largest and most dangerous competitor.
D) They wanted to share their assets in order to maintain liquidity in times of financial panic.
E) They were sharing patents for new technologies in the railroad industry.