I'm pretty sure that your answer is the Distributive Property, if I were you, I'd check your notes if you have notes or anything, and THEN, search it up. Just to make sure. I'm not always a hundred percent sure of my answer, but, I *THINK* it's the distributive property.
Let's move the terms with n to one side:
12n < 3n + 28 => 12n - 3n < 28
9n < 28 => n < 28/9
n < 3.1111
The only answer which satisfies this inequality is A.
Answer:
I don't think this question can be answered without more info