In the Case of the Fruit Flies with Photographic Memory

In the case of the fruit flies with photographic memory, what was responsible for their extraordinary ability to remember something after only a single exposure?

A) The flies were rewarded with sugar after exposure to the stimulus"
B) Excess amounts of a plasticity, spatial memory, and long-term memory forming protein in the postsynaptic neuron"
C) The pairing of the stimuli with an electric shock"
D) An abundance of new neurons were formed and released immediately after exposure to the stimulus"