Final answer:
The most useful piece of data for an ambitious photographer looking to expand their business outside of Georgia and offer spring and holiday portrait packages to elementary schools is the school holiday calendar.
Step-by-step explanation:
The most useful piece of data for an ambitious photographer looking to expand their business outside of Georgia and offer spring and holiday portrait packages to elementary schools is option D, the school holiday calendar.
Knowing the school holiday calendar will allow the photographer to plan their availability and schedule accordingly. They can align their portrait sessions with the holidays when students and parents are more likely to be available and interested in booking a session. This data will help the photographer maximize their business potential and cater to the needs of their target market.