So 4/5 should be an 80 because if you multiply 5x20 and 4x20 you would get 80/100 but sometimes teachers make certain questions worth more points than others so maybe that is what happened but maybe talk to your teacher about it
I do not see all the graphs but it would be the reverse of what is shown for A. graph. The tickets sold to total income would have to be a 1:4 ratio where every 4 dollar leap in the y-axis is a one point (1 unit change in x).