The following graph shows the mortality risk of a disease with respect to parameters A and B.

Which of the following combinations of parameters is associated with the lowest mortality risk?

Correct option is A

Observations:

1. Parameter A Values: 100, 160, 220
2. Parameter B Values: 25, 45, 65, 85
3. The bars represent mortality risk percentages, with shorter bars indicating lower risks.

Step-by-Step Analysis:

1. From the graph, the lowest bar (indicating the lowest mortality risk) is located at:

   • Parameter A = 100
   • Parameter B = 85

2. The difference between A and B for this combination is:
   A - B = 100 - 85 = 15

3. This value (15) is the lowest value of A - B across all parameter combinations.

Final Answer:

The correct option is (a):
"The lowest value of A - B."