However, you "<em><u>could</u></em>" say #4 in the sense that writing <em><u>can</u></em> be used to convey shock (but the purpose of writing a simple sentence is not necessarily to convey shock), and while ALL writing should reflect clarity, the purpose of a simple sentence is not necessarily to do that.
Explanation:
The question asks for "best"... so that implies ONE answer (thus, #2).