Which sentence demonstrates correct subject and verb agreement​

12 read the sentence below and answer the question that follows. why is elementary school success an indicator of graduation rates? why is this sentence not a thesis statement? it is not a debatable topic. it is a question it is an opinion it is not a fact mark this and retum

American history (is, are) studying the american colonies.

To meet the needs of commuters in the industrial age, city planners implemented the use of phonographs. provided more horses and carriages. borrowed technology from railroads. constructed new telephone lines.