A second hand car dealer has 7 cars for sale. She decides to investigate the link between the age of the cars, x years, and the mileage, y thousand miles. The date collected from the cars is shown in the table below.

Age, x Year	2	3	7	6	4	5	8
Mileage, y thousand	20	18	15	24	29	21	20

Find the least square regression line in the form y = a + bx.

a. Y= 43 + 10 X

b. Y= 23- 0.4 X

c. Y= 10 + 53 X

d. Y= 23 + 4 X