Choose the method of pay that would result in the most earnings for one month on sales of $40,000. a. Straight commission of 7.5% on all sales. b. Monthly salary of $1,600 plus 2.5% commission on all sales. c. Graduated commission of 5% on the first $30,000 in sales and 6% on anything over that. d. Graduated commission of 4% on the first $25,000 in sales and 8% on anything over that.

the height of the surface increases from the center out to the sides of the road.

step-by-step explanation:

as we move out we move away from the x-axis.

and as mentioned in the problem statement that height of a road increases when we move away from the center x.

hence proved that 3rd option

the height of the surface increases from the center out to the sides of the road.

is the correct option.