Final answer:
The method of delivering medicine directly into the bladder is intravesical instillation. It involves instilling medication directly into the bladder through a catheter.
Step-by-step explanation:
The method of delivering medicine directly into the bladder is intravesical instillation. This involves instilling medication directly into the bladder through a catheter.
Intravenous injection (option 1) is used to deliver medicine directly into a vein, while intramuscular injection (option 2) is used to administer medicine into the muscle. Intradermal injection (option 4) is used for skin testing or to administer small amounts of medication.
Therefore, the correct answer is option 3, intravesical instillation.