Read the excerpt from The Boy Who Harnessed the Wind by William Kamkwamba. News of the machine had spread to the villages, and people were starting to arrive. The traders spotted it from their stalls and packed up their things. The truckers left their vehicles along the roads. Everyone walked into the valley, and now gathered in its shadow. I recognized these faces. Some of these people had mocked me for months, and still they whispered, even laughed. More of them were coming. It was time.

What is the main function of this excerpt?

It introduces the windmill.
It introduces the conflict.
It introduces the author.
It introduces the resolution.