Final answer:
Mr. Martin most likely made a change to the business name from Martin's Flowers to Flowers Galore for rebranding purposes, not necessarily indicating any change in location, ownership, or product line.
Step-by-step explanation:
If Mr. Martin's shop was originally called Martin's Flowers and is now called Flowers Galore without any other context, the change that Mr. Martin most likely made is (d) Change of business name. This type of change typically signifies a rebranding effort to possibly refresh the store's image, attract more customers, or signal some change in the direction or expansion of the business. Changing the name does not necessarily mean a change of location, ownership, or product line, though those could also happen concurrently.