I would go with C. Because the narrator is talking. The narrator want to have a lesson badly on water-reading. But Mr. Bixby thinks the narrator is far to advanced for it and will not teach her it. So Mr. Bixby is being stubborn and will not give the lesson.
First person
It takes a bit of reading into the passage to see what point of view it is, because there is little indication in the first paragraph. The first indication that it is written in first person is the use of "us" at the end of that first paragraph. Then, in the subsequent paragraphs the reader sees that the author uses "I" several times, indicating first person perspective.
English most likely, but sometimes they surprise you with Japanese.
Answer:
Between failed and so.
"In 2021, three national power grids in India failed, so hundreds of millions of people were left without power."