Which graph represents an increasing function?
four graphs of y against x are shown. the title for the first graph is graph a, the title for the second graph is graph b, the title for the third graph is graph c, and the title for the fourth graph is graph d. graph a is a straight line joining the ordered pairs 0, 4 and 5, 0. graph b is a straight line joining the points 0, 0 and 5, 5. graph c is a straight line joining the points 0, 3 and 5, 3. graph d is a straight line joining the points 5, 0 and 5, 5.
graph a
graph b
graph c
graph d