The inequality is C < 18, and the graph can be seen at the end of the answer.
We know that ]Ezra used 18 oz of cheddar, and he wants to use less cream cheese than cheddar, then if C represents the amount of cream cheese that he uses, we need to have:
C < 18 oz.
This means that C must be strictly smaller than 18 ounces. (While the option that you have marked means that C can be less than or equal to 18 oz).
To graph this, you need to graph a white dot in number 18 (for the symbols > and < we use open or white dots), and a line that extends to the left. (there is an example of the graph below).
If you want to learn more about inequalities, you can read:
https://brainly.com/question/11234618