user
Dr.  Garrison has told all the towns people that he will get across Grass Lake with no assistance.  He told everybody to meet him at Grass Lake on Sunday at 12:00.  So when everybody showed up on Sunday, Dr. Garrison finished his task by getting across Grass Lake.  How did he do it?
A: hike
B: grass lake was frozen
C: niagara
D: see
E: territorial waters
assistant
<|begin_of_thought|>

Deep Thought is thinking for 7.5 million years.

<|end_of_thought|>

<|begin_of_solution|>

B

<|end_of_solution|>