In the Image Above Is an Autoradiograph of the Left

In the image above is an autoradiograph of the left hemisphere of a mouse brain after radioactive 2-DG injections taken after the mouse had just completed a memory test in an 8-arm radial maze. Would you assume this mouse had just started training or was several days into the training to remember which arm contained food?

A) just started training
B) several days into training
C) the autoradiograph can not be used to determine this
D) somewhere between the first and last days of training