To calculate the sales tax that Bailey will owe, you can use the following formula:
\[ \text{Sales Tax} = \text{Cost} \times \text{Sales Tax Rate} \]
In this case, the cost of the food and coffee is $21.25, and the sales tax rate is 9% (or 0.09 in decimal form).
Now, plug in the values:
\[ \text{Sales Tax} = 21.25 \times 0.09 \]
Calculating that:
\[ \text{Sales Tax} = 1.9125 \]
Since sales tax is typically rounded to two decimal places, it will be approximately $1.91.
So, the correct response is $1.91.