The most relevant similarity between blood cells and stomach cells from the options provided is:
Both help maintain homeostasis.
Blood cells play a crucial role in transporting nutrients, gases, and waste, thus helping to regulate various body functions and maintain a stable internal environment. Stomach cells, on the other hand, produce gastric juices and enzymes that aid in digestion, which is essential for nutrient absorption and overall metabolic balance, contributing to homeostasis as well.
The other options do not accurately represent a similarity between blood cells and stomach cells; for instance, blood cells do not secrete enzymes nor are they primarily involved in digestion, while stomach cells primarily focus on that function.