Answer:
Provide information, give an opinion, give directions, and propose an action are examples of the purpose in writing.
Step-by-step explanation:
The word "purpose" refers to what one seeks to achieve; objective, purpose, purpose.
When a person writes something, that person is trying to achieve something, that is, that person has a purpose to be achieved with his writing. This may be to provide information, to give an opinion, to give instructions or to propose an action, for example.
For this reason, we can conclude that the word that best completes the blank in your question is "purpose."