Explanation: B is an experience and doesn't give us a reason why, C is just the fact that other people have been doing it, and D is a comeback to a common objection to journal writing.
A good way of thinking about it is that A is the direct reason, and the rest is sort of supporting evidence. A would be the topic sentence in a persuasive essay, and the rest might come after it.
Each column is called a group. The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons.
Whenever repetition is used, it is used to bring attention to the main point, and to make it more memorable in the listener's minds. This makes you remember this phrase more, and makes you more likely to agree with it.
