Final answer:
The inequality that could be used to find the number of bags of cat treats that Sarah could've bought is 22 + 4b ≤ 35.
Step-by-step explanation:
The inequality that could be used to find the number of bags of cat treats that Sarah could've bought is A) 22 + 4b ≤ 35. Since Sarah bought a cat backpack for $22, the total amount she spent cannot exceed $35. Since the bags of cat treats cost $4 each, the number of bags of cat treats that Sarah could've bought is represented by the variable b. Therefore, the inequality 22 + 4b ≤ 35 would give the possible range of values for b.