Final answer:
Glandular cells with an extensive network of smooth endoplasmic reticulum are most likely to produce steroid hormones, considering that smooth endoplasmic reticulum is essential for lipid and steroid synthesis.
Step-by-step explanation:
Examination of a sample of glandular cells with an extensive network of smooth endoplasmic reticulum (SER) suggests that such cells are likely involved in lipid-related processes. The SER is integral in the synthesis of steroids, phospholipids, metabolism of carbohydrates, detoxification of medications and poisons, and regulation of cellular calcium ions. Glandular cells with a prominent SER are typically associated with steroid hormone production.
Given the functions of the SER, the likely product of these cells would be steroid hormones. Other potential products and functions, such as enzymes for digestion, structural proteins, and antibodies, are more commonly associated with the rough endoplasmic reticulum, which is characterized by the presence of ribosomes for protein synthesis.