Final Answer:
Arrow 4 (D) points to the pituitary gland.
Step-by-step explanation:
In the absence of a visual representation, the correct identification relies on understanding the anatomical context. The pituitary gland, also known as the master gland, is a small, pea-sized structure located at the base of the brain, within the sella turcica of the sphenoid bone. When presented with arrows pointing to different areas, one must visualize the anatomy and consider the region where the pituitary gland is typically situated. Arrow 4 (D) is likely to be directed towards the sella turcica region, indicating the location of the pituitary gland within the brain.