What step did the populist party support to reduce the cost railroad shipping?

They had the national government control the railroads.

Explanation:

One of the ways in which the Populist Party supported the reduction of the cost of railroad shipping was by having the national government control the railroads. By giving control to the government, the party hoped that regulations would increase. In turn, these regulations would be able to manage how high costs could get through various policies or subsidies.

your answer would be just capitalism.

b. the passage of the equal rights amendment  

explanation:

this mean that anything that someone else could do they could do