How did city infrastructure in the early 20th century affect the modernization of firefighters?

How did city infrastructure in the early 20th century affect the modernization of firefighters? (Check all that
apply.)
AThe training for firefighting opened more job opportunities.
B The city became the main overseer of all firefighting duties and jurisdictions.
CTechnology changes brought improvements to fire engines.
DWater hydrants and reservoirs were planned with the city’s development.