**Core Concept**
Exstrophy of the bladder is a rare congenital anomaly characterized by the abnormal exposure of the bladder mucosa outside the body due to a failure of the abdominal wall to close during fetal development. This condition is associated with various genitourinary and pelvic abnormalities.

**Why the Correct Answer is Right**
The key features of exstrophy of the bladder include:
* **Eversion of the bladder mucosa**: The bladder mucosa is exposed outside the body due to the abnormal development of the abdominal wall.
* **Ureterocele**: The distal ureters often form a ureterocele, which is a cystic dilation of the distal ureter.
* **Ectopic ureters**: The ureters may be ectopically located, meaning they open outside the bladder.
* **Prostatic utricle**: The prostatic utricle, a small indentation in the prostate gland, is often enlarged.
* **Abnormal genitalia**: Males may have undescended testes, hypospadias, or epispadias, while females may have a short or absent urethra.

**Why Each Wrong Option is Incorrect**
**Option A:** Not all exstrophies of the bladder are associated with a **sacrosciatic defect**. While this is a common finding, it is not a universal feature.
**Option B:** **Ectopic ureters** are indeed associated with exstrophy of the bladder, but this is not the correct answer because it is a feature of the condition, not an exception.
**Option C:** **Ureterocele** is also a feature of exstrophy of the bladder, making it an incorrect answer.
**Option D:** **Prostatic utricle** is an enlarged structure in exstrophy of the bladder, so this is not the correct answer.

**Clinical Pearl / High-Yield Fact**
Exstrophy of the bladder is often associated with other genitourinary abnormalities, such as **epispadias** or **hypospadias**, which can be remembered using the mnemonic **"EVE"** (Exstrophy, Epispadias, and Vaginal duplication).

**Correct Answer: A.**