Fortunately, the rules necessary to resolve the equation in this post are extremely elementary, so none of what you’re referencing has any bearing whatever.
There are exactly three things to consider in here to determine priority: parentheses, multiplication/division, and addition. The addition happens first due to the parentheses, and the remaining is evaluated left-to-right. The only correct answer here is 16.
All your deflection from your embarrassment at misreading a simple equation doesn’t detract from this.