Answer:
A fruit fly of 75h AEL is at larval stage.
Explanation:
The development of a Drosophilia starts from egg to larva to pupa then to adult. The full development at 25 degrees Celsius takes between 8.5 to 10 days. The higher the temperature, the faster the development of the Drosophilia.
The eggs hatch after 12-15 hours into larval stage which then lasts for 3-4 days(72-96 hours) then the pupal stage which also lasts for 3-4 days before it becomes a full adult.
Thus, 72 hours after egg laying would still be in larval stage. The larval stage ends after at leas 90 hours after egg laying.