**Core Concept**
The urinary bladder's musculature is innervated by the autonomic nervous system, specifically the pelvic splanchnic nerves and the hypogastric plexus. This dual innervation allows for voluntary control over bladder function.

**Why the Correct Answer is Right**
The pelvic splanchnic nerves, which arise from the S2-S4 sacral spinal cord, carry parasympathetic fibers that stimulate bladder contraction and relaxation of the internal urethral sphincter. In contrast, the hypogastric plexus, which receives sympathetic input from the T11-L2 spinal cord, promotes bladder relaxation and contraction of the external urethral sphincter. This interplay between parasympathetic and sympathetic inputs enables voluntary control over urination.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specify the correct nerve supply to the urinary bladder's musculature.
**Option B:** This option is incorrect as it does not accurately describe the nerve supply to the urinary bladder's musculature.
**Option D:** This option is incorrect as it does not specify the correct nerve supply to the urinary bladder's musculature.

**Clinical Pearl / High-Yield Fact**
During pelvic surgery, the pelvic splanchnic nerves should be preserved to maintain bladder function and prevent postoperative urinary retention.

**Correct Answer: C. Both the pelvic splanchnic nerves and the hypogastric plexus.**