The total cost and total revenue function of a commodity are given by C(x) =x+40 and $R(x) =ax-bx^2$.Break-even points are 5, 40 then a and b are :

$a=2, b=10$ $a=10, b=0.2$ $a=2, b=0.1$ $a=1, b=0.2$

$a=10, b=0.2$