Which problem can be solved using this inequality?

x + 5 ≤ 20
A.
Beth is purchasing school supplies. She knows that the price for her pencil case is $15. She only has $20 to spend. How much money will she have left after buying the pencil case?
B.
Beth is purchasing school supplies. She knows that the price for her pencil case is less than $5. She only has $20 to spend. How much money will she have left to spend after buying the pencil case?
C.
Beth is purchasing school supplies. She knows that the price for her pencil case is $5 more than the cost of a book bag. She only has $20 to spend. Does Beth have enough money to buy the pencil case and book bag?
D.
Beth is purchasing school supplies. She knows that the price for her pencil case is $5. She only has $20 to spend. What is the most amount of money she can spend on the remaining supplies?