Answer:
The answer is: A) core competencies that have become core rigidities.
Step-by-step explanation:
The core competencies of a business are what makes that business have an strategic advantage over its competition. In this case, the store sells the best high quality fabrics.
In the past the store had an strategic advantage since they sold a great product, but nowadays very few people are interested or willing to buy their fabrics. So what once was a core competency has now become a core rigidity. The store relied for too long on their core competency until it became obsolete. A textbook example for this is Kodak and its photographic film.