birds flying south in the winter plants flowering in the summer trees losing their leaves in the fall earthworms living underground all year
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which of the following is an example of organisms becoming dormant?
Possibilities:
- birds flying south in the winter
- plants flowering in the summer
- trees losing their leaves in the fall
- earthworms living underground all year

trees losing their leaves in the fall