Final answer:
All of the substances listed, including potassium ions (K+), glucose, and calcium ions (Ca2+), can act as humoral stimuli for hormone release because they can influence changes in ion concentration or solute levels in the blood, prompting a regulatory hormonal response.
Step-by-step explanation:
The substances that might act as humoral stimuli for hormone release include K+ (potassium ions), Glucose, and Ca2+ (calcium ions). Therefore, the correct answer is D) All of the above. This is because humoral stimuli involve the control of hormone release in response to changes in extracellular fluids such as blood or the ion concentration in the blood.
For example, a rise in blood glucose levels triggers the pancreatic release of insulin as a part of a negative feedback loop. Similarly, calcium and potassium ions can also participate in signaling mechanisms that result in the release of hormones to regulate physiological processes and maintain homeostasis in the body.