In 1984 why do you suppose the government would frown up the writing of a diary

In the book 1984 some of the elements of the story included "Thought Police" who were controlling people's thoughts and activities. A diary would be a reflection on one's life and experiences and could lead to undesirable thoughts that would be difficult to detect and counter or control.

Iwould say a, due to the fact these routes display many things that would be useful and provide explanations for how states are known.