8x+6y≤172 subtract 8x from both sides
6y≤172-8x divide both sides by 6
y≤(172-8x)/6
y≤(86-4x)/3
So the graph will be everything under and including the line y=(86-4x)/3
If those two graphs are your choices, and the easiest way to spot the correct one is just to solve when x=0. y(0)=86/3=28 2/3
So the y-intercept is 28 2/3, which is clearly not graph A (about 21), and is graph B.
