Brainliest to the right answer. Plz answer if you know and not just for points

Answer:
A
Step-by-step explanation:
the price has to be equal to or less than 21 dollars so he can buy all tge food, so you know that the sign will be <.
you know it will be 5 instead of 3 because 5 is how kuch it costs, and youre finding the price.