**Core Concept**
Transitional cell carcinoma (TCC) of the bladder is a type of urothelial cancer that arises from the bladder lining. Stage II TCC is characterized by the tumor invading the muscle layer of the bladder wall, but not extending beyond it. Management of TCC involves a multi-modal approach, including surgical resection, chemotherapy, and immunotherapy.

**Why the Correct Answer is Right**
In stage II TCC, surgical resection with cystectomy (removal of the bladder) is often the primary treatment. This is because the tumor has invaded the muscle layer, increasing the risk of recurrence and metastasis. Neoadjuvant chemotherapy may be administered before surgery to shrink the tumor and improve surgical outcomes. Adjuvant chemotherapy may also be given after surgery to reduce the risk of recurrence. Radical cystectomy with pelvic lymph node dissection is the standard surgical approach for stage II TCC.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because stage II TCC is not typically managed with radiation therapy as the primary treatment. While radiation may be used in combination with chemotherapy or as an adjuvant therapy, it is not the primary treatment for stage II TCC.
**Option B:** This option is incorrect because endoscopic resection (such as transurethral resection of bladder tumor, TURBT) is not sufficient for stage II TCC, as the tumor has invaded the muscle layer. Endoscopic resection may be used for early-stage TCC or as a diagnostic tool, but it is not the primary treatment for stage II TCC.
**Option D:** This option is incorrect because bladder-sparing approaches, such as organ preservation therapy, may be considered for select patients with stage II TCC, but they are not the standard treatment. Organ preservation therapy involves using chemotherapy and radiation to shrink the tumor, followed by a bladder-sparing approach.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the management of TCC depends on the stage and grade of the tumor, as well as the patient's overall health and performance status. A thorough evaluation and discussion with a urologist and oncologist are necessary to determine the best treatment approach.

**Correct Answer: C.**