Final answer:
The largest classification of shopping center is regional center, which is practically a city under a roof attracting shoppers from miles around.
Step-by-step explanation:
The answer to the question is A) Regional. Regional centers are the largest classification of shopping centers. These centers are like cities under a roof and attract both local and one-time shoppers from other areas. Examples of regional centers include malls like the Mall of America in Minnesota or the Westfield Garden State Plaza in New Jersey.