It can't be A, B, nor C because some of the equations wouldn't have a straight line if displayed in a graph. For example A has a square root symbol and b and a have an exponent they would create a perebula where that would mean the equations would not make a straight line. However, Choice d doesn't have any exponents, or square root symbols meaning the equation could slope up or down in a STRAIGHT line in a graph.
1/4 equals 0.25 gallons, 1/2 gallons is 0.5, so Will will have a mix of 0.75 gallons. If each serving is 1/16 and 1/16 equals 0.0625, divide 0.75 by 0.0625 = 12 servings.
