Step 1: Concept
Dispensing labels are designed to provide clear instructions to the patient and healthcare providers regarding the medication.
Step 2: Meaning
Labels must include safety-critical information such as drug identity, potency, and dosage instructions.
Step 3: Analysis
The name, strength, and quantity of the drug are essential for correct administration. However, the specific "cause of illness" (diagnosis) is considered sensitive clinical information and is not standardly included on a medication label.
Step 4: Conclusion
Therefore, the cause of illness is the element that should not be on the dispensing label.
Final Answer: (B)