Answer:
OD. The price of other products would need to have increased.
Step-by-step explanation:
Inflation is defined as the decline of the purchasing power of a particular currency over a period of time. Which means that if a product cost $1 last two years and now costs $2 now, and its effect is also felt among other commodities, then inflation is confirmed as it is not limited to a particular product.
Therefore, if ten years ago, a smoothie at Kay's Smoothies cost $1.25 and today it costs $2.00, in order to attribute this price increase of smoothies at Kay's to inflation, the price of other products would need to have increased.