Joseph plans on increasing his grade in math. The function y = 80 + 2x represents his grade, y, after x weeks.What is the meaning of the slope of the line?A.He increases his grade by 1 point every 2 weeks.B.He increases his grade to an 80 in 2 weeks.C.His initial grade was an 80.D.He increases his grade by 2 points each week.