One cannot paddle down a river if it is frozen over.
This justifies what answer for what question? Q & A: 
Can we conclude from "Three people paddle down a river through tall grass in a canoe." that "The river is frozen over."?
Options:
- yes
- no
- it is not possible to tell
no
One cannot paddle down a river if it is frozen over.
This justifies what answer for what question? Q & A: 
user
Can we conclude from "Three people paddle down a river through tall grass in a canoe." that "The river is frozen over."?
Options:
- yes
- no
- it is not possible to tell
no
assistant
One cannot paddle down a river if it is frozen over.
This justifies what answer for what question? Q & A: 
Can we conclude from "Three people paddle down a river through tall grass in a canoe." that "The river is frozen over."?
Options:
- yes
- no
- it is not possible to tell
no