Read this passage from "Rider in the City."

"This is a good supper," said Rider, hoping to distract his sister from her anger.

"It's not 'supper,'" she said tensely. "It's 'dinner'!"

Based on this excerpt, Rider's sister is annoyed because

Rider speaks differently than she does.
Rider thinks he's better than her.
Rider lives with their father instead of her.
Rider is unappreciative their mother's cooking.

Rider speaks differently than she does.

Based on this excerpt, Rider's sister is annoyed because Rider speaks differently than she does.

Based on this excerpt, we can determine that Rider's sister is annoyed because Rider speaks differently than she does. In the passage, Rider refers to the evening meal as "supper," while his sister corrects him and insists that it's called "dinner." This suggests a difference in dialect or regional language usage between the two siblings, which is causing annoyance or tension.