The correct option is this: WRITING IS DIFFICULT BECAUSE SO MANY SKILLS ARE INVOLVED.
A topic sentence refers to the sentence which expresses the main idea of the paragraph in which it occurs. The topic sentence is usually the opening sentence in the paragraph; the other sentences in the paragraph just serve to support the topic sentence.
The persuasive techniques that are used in the statement given is a hasty generalization and loaded words. The correct answer is D.
We have to know more about the story to answer this