Answer:
C
Step-by-step explanation:
On the horizontal axis, as the discount (%) increases by 1(%), on the vertical axis; the sales increase (%) increases by 3(%).
When the discount is 10%, the sales increase is 32%.
When the discount is 20%, the sales increase is 62%.
20 - 10 = 10
10 × 3 = 30
32 + 30 = 62 (correct)
