Choice A is the correct answer. Inequalities with variables on both sides require combining like terms.

1. Subtract 4x: $8x - 4x + 12 \leq 4x - 4x + 28$, giving $4x + 12 \leq 28$
2. Subtract 12: $4x + 12 - 12 \leq 28 - 12$, giving $4x \leq 16$
3. Divide by 4: $x \leq 4$

?�� Strategic Tip: To solve inequalities with variables on both sides, move all variable terms to one side and all constants to the other.

Choice B is incorrect because it reverses the inequality without mathematical justification. Choice C is incorrect because it might come from adding 12 and 28 to get 40, then dividing by 4. Choice D is incorrect because it combines wrong value (10) with wrong direction ($\geq$).