In the given question Laura has $30 to spend on food for the week.
According to the question we have to set the inequality between total amount and amount spent on food.
Amount spend by Laura on food for the week = $30
Let the amount spent by Laura on food be x
So she has to spend up to $30
So inequality will be 
So option b is the answer
I think it’s c but don’t go with me see if others answer with a different answer :)
Its the difference between the y- values divided by the distance between the corresponding x values. Or its sometimes called rise / run.
The 2 fractions are the possibilities
FD/CA = EF/BC
x/(8.5 mm) = (12 mm)/(4 mm)
x = (8.5 mm)*(12/4)
x = 25.5 mm . . . . . . . . . . . the 3rd selection