Krissy's becomes active when she tries to recall what she received for christmas when she was 10 years old. successful remembering of this information, however, requires the activity of the

The answer is: Frontal lobe; hippocampus
Frontal lobe controls all of our conscious actions. So, when we initiate the effort to remember, our frontal lobe would be activated.
Hippocampus had the function to control our long-term memory. After the frontal lobe activation, we need our hippocampus to activate and differentiate the relevant memory.