First, in order for a line to be horizontal, it must have a slope of 0. Therefore, based on the formula y=mx+b, x will not be in the answer since m=0. So that means the answer is either A or B. Now you can think about it like this: any equation that is y equals some value would always have the same y value no matter what the x value is. So in order for the point (1,14) to be on the line, the y value would always need to be 14 so the answer is y=14.
Hope this helps