What does the underlined portion in the Tule geese text illustrate?

• A. A change in Tule geese's usual flight behavior
• B. A stable migration pattern
• C. A decline in population
• D. A shift in feeding habits

Answer: (A)

The main idea being tested is how to read for a change in behavior rather than other aspects like population or diet. When the text highlights a part about how the Tule geese move—their route, timing, altitude, or speed—it signals a departure from what they normally do during migration. That kind of detail shows a shift in flight behavior, such as taking a new path, flying differently, or adjusting pace in response to weather or obstacles. It isn’t describing how many geese there are, nor what they eat, nor a steady, unchanging pattern. So the underlined portion best illustrates a change in flight behavior.