Answer:
Below.
Step-by-step explanation:
The root "infer" means to deduce, to conclude. And the word "inferior" means something that is lower, lesser in quality, of a low position, etc.
In the use of the word "inferior" in the sentence "[a]fter the change of management, the store began to offer inferior products", we can deduce that the word meant "a lower quality", which can be related to the word "below". So, the sentence meant to say that after the management changed, the store began to offer lesser quality products. This means that the store gave goods that are below the expected or normal quality.
Thus, the correct answer is "below".