We have the next informations
1990 ------ 2400
2000-------- 4000
the year 1990 represents x=0
for 2000 passed 10 years son x=10
we have then the next points
(0,2400) =(x1,y1)
(10,4000) =(x2,y2)
First we need to calculate the slope
then we can calculate the linear equation
the linear equation is
the correct answer is B