The graph shows the cost, in dollars, of a phone call for different call durations. The x-axis represents call length (minutes), and the y-axis represents call cost.

What does this tell you?
Choices:
A:The cost of a call increases by $\$ 0.90$ for each additional minute
B:Each additional dollar will buy an additional 0.9 minutes of call time
C:The cost of a call decreases by $\$ 0.90$ for each additional minute
D:Each additional dollar will buy 0.9 minutes less of call time than the previous dollar
Please directly answer the question and provide the correct option letter, e.g., A, B, C, D.
Question: The graph shows the cost, in dollars, of a phone call for different call durations. The x-axis represents call length (minutes), and the y-axis represents call cost.

What does this tell you?
Choices:
A:The cost of a call increases by $\$ 0.90$ for each additional minute
B:Each additional dollar will buy an additional 0.9 minutes of call time
C:The cost of a call decreases by $\$ 0.90$ for each additional minute
D:Each additional dollar will buy 0.9 minutes less of call time than the previous dollar
Please first conduct reasoning, and then answer the question and provide the correct option letter, e.g., A, B, C, D, at the end.
Question: The graph shows the cost, in dollars, of a phone call for different call durations. The x-axis represents call length (minutes), and the y-axis represents call cost.

What does this tell you?
Choices:
A:The cost of a call increases by $\$ 0.90$ for each additional minute
B:Each additional dollar will buy an additional 0.9 minutes of call time
C:The cost of a call decreases by $\$ 0.90$ for each additional minute
D:Each additional dollar will buy 0.9 minutes less of call time than the previous dollar