Final answer:
The question's anatomical references are unclear, but it may be related to the carpal tunnel and metacarpal bones forming the palm of the hand.
Step-by-step explanation:
The area of the hand that is between the apex and the back of the parietal ridge is not a standard anatomical description. However, the question could be referring to the carpal bones that form the base of the hand, particularly those located in the area commonly referred to as the carpal tunnel.
The carpal tunnel is the passageway that allows muscle tendons and the major nerve to enter the hand from the anterior forearm. The metacarpal bones form the palm of the hand and lie between the carpal bones and the phalanges of the fingers and thumb.
By context, if using 'apex' to refer to the distal aspect (toward the fingertips) and 'parietal ridge' to refer to a more proximal landmark (near the wrist), the student could conceivably be asking about the metacarpal area.