That is false. You can use a P.S. (post script) at the end of a business or formal letter, but it is uncommon.
A topic sentence presents the main gist of the whole paragraph or article. So, if you want to talk about building a snowman, your topic sentence could be about why building snowmans are of relevance. Then, your supporting details could now include steps or advices on how to build it.
A good topic sentence I could think of is:
<em>During the yuletide season, building a snowman is a good activity to do with family and friends because it promotes team-building and fun interaction.</em>
It depends on which version you watch/read. The two movies I have are by two different people, and in one, she screams AND eats cake. in the other, she screams and talks to herself.
C. The sentences are of the writer's own voice and thought and not cliche or verbal generalities.