The bar graph below shows the percentage of students who received each letter grade on their last English paper. The class contains 40 students. [Graphs generated by this script: setBorder(28,45,0,10); initPicture(0,10,0,50);axes(1000,10,1,1000,10); fill="blue"; stroke="black";textabs([165,0],"Grades","above");rect([1,0],[3,20]);text([2,0],"A","below");rect([3,0],[5,50]);text([4,0],"B","below");rect([5,0],[7,10]);text([6,0],"C","below");rect([7,0],[9,20]);text([8,0],"D","below");] What number of students earned a B on their paper? students