I'm not sure 100% what exactly this question is asking, but I know World War 1 was the first war to include Gas masks and Chemical warfare, so that is more than likely the answer.
The populism movement took hold because the use of the gold standard was causing many people to lose money - especially farmers. Farmers were having a lot of trouble because there were no regulations put in place to help them not produce too much it too little. Also, the populism movement promoted the regulation of railroad prices. That way, farmers could ship their produce at cheaper price points.
The answer is the third one: it promoted reforms to help struggling farmers
Answer:
The branch of science and technology concerned with the properties of metals and their production and purification.
Explanation: