Connotation is a feeling that happens inside you when you see a word.
Formal.
As far as I know, there is no such thing as either standard or practiced diction. Informal is the way you communicate with your friends, for instance, which is not how you would write a thesis paper, legal document, etc.
Answer:
"Daniel was a faithful young man."
Explanation:
This presents the topic that will be supported with details in the paragraph.