The given pie-chart shows the data on A, B, O, and AB blood groups of 240 donors. Study the chart and answer the question that follows.
What is the ratio of the average donors of blood groups 'A', 'O', and 'AB' to the donors of blood group 'B'?
1
3 : 4
2
4 : 3
3
2 : 3
4
1 : 3