Scientists have steadily increased the amount of grain that farms can produce each year. The yield for farms in France is given by y=−2.73x^2+11000x−11000000 where x is the year and y is the grain yield in kilograms per hectare (kg/ha). What does the y-intercept of this function represent?

A. the increase in crop yield every year

B. the crop yield in year zero

C. the crop yield for a given year

D. the crop yield in 1960