help the plant to get moisture. anchor the plant in the ground. protect the plant from harm. support the stems and branches.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: The purpose of thorns on a plant is most likely to
Possibilities:
- help the plant to get moisture.
- anchor the plant in the ground.
- protect the plant from harm.
- support the stems and branches.

protect the plant from harm.