Earlier Research on the Timing of Synapse Production and Elimination

Earlier research on the timing of synapse production and elimination failed to show the changes at adolescence because:

A) only males were examined.
B) the same individuals were not followed over time.
C) adolescents often fail to comply with important procedural instructions.
D) the brains of adolescents are too mature for examination with child measures and too immature for examination with adult measures.