A consumer group is investigating the relationship between sugar content and number of calories for different brands of cereal. The equation of the line of best fit for the data is y = 4x + 80, where x is the number of grams of sugar and y is the number of calories in one serving. What is the meaning of the y-intercept in the line of best fit?

A. Out of all the brands of cereal, the greatest number of calories in one serving was 80.
B. The number of calories in one serving is estimated to be 80 if there is 0 grams of sugar.
C. Out of all the brands of cereal, there were 0 brands of cereal that had 80 calories in one serving.
D. The number of calories in one serving is expected to increase by 80 for each increase in 1 gram of sugar.