Question

choose the best idea to add to a summary of \a village on the move.\
the people of newtok were forced to leave their town.
erosion caused by the rising river has made newtok unsafe.
there used to be a lot of permafrost in alaska.
frozen soil under the ground, called permafrost, is melting.

Explanation:

A summary should capture the main idea. The first option is a result (people forced to leave), but the second option (erosion from rising river making Newtok unsafe) is the cause - and - effect relationship that likely drives the narrative of the story "A Village on the Move". The third option is too general about Alaska's permafrost (not specific to Newtok). The fourth option is about permafrost melting but not directly tied to the village's situation as clearly as the second option.

Answer:

Erosion caused by the rising river has made Newtok unsafe.