A biologist measured average tail length (in cm) for four squirrel populations across forest types: dense oak, 19.2; sparse oak, 17.8; dense pine, 13.5; sparse pine, 13.1. She concluded that tree type affects squirrel tail length more than tree density does. The strongest support is ______
Which choice most logically completes the text using the data above?
- A
sparse pine's tail length of 13.1.
- B
the average across populations.
- C
dense oak's tail length of 19.2.
- Dcheck_circle
the comparison: oak-vs-pine differences (5.7 cm in dense, 4.7 cm in sparse) versus dense-vs-sparse differences (1.4 cm in oak, 0.4 cm in pine)—tree type shifts tail length by 4-6 cm, while density shifts it by less than 2 cm.
Explanation
"Tree type affects tail length more than density" requires comparing each variable's effect while holding the other constant. Choice B does both and shows tree type shifts tail length much more than density does.