The distributive property allows us to go from the original expression to choice A. We multiply the outer term 8 by each term inside the parenthesis.
In general, the distributive property is a(b+c) = ab+ac. Example: 2(3+4) = 2(3)+2(4) = 6+8 = 14.
After simplifying the expression in choice A, it leads directly to choice E. This is because 8(6x) = 48x and 8(9) = 72.
Side note: A common mistake students do is to multiply the outer term by only one of the terms inside the parenthesis, while forgetting about the other term inside. Choice B shows this mistake. It's possible your teacher put choice B in there as a trap/trick answer.
