**Core Concept**
Prostatism refers to the urinary symptoms caused by an enlarged prostate gland. The assessment of patients with prostatism typically involves a combination of medical history, physical examination, and diagnostic tests to determine the cause and severity of the symptoms.

**Why the Correct Answer is Right**
The correct assessment of patients with prostatism includes a digital rectal examination (DRE) to evaluate the size and consistency of the prostate gland, as well as to detect any nodules or tenderness. Additionally, patients may undergo urinary flow studies to assess the rate of urine flow, and post-void residual (PVR) urine volume measurements to evaluate the effectiveness of urination. These tests help to identify the underlying cause of the symptoms, such as benign prostatic hyperplasia (BPH) or prostatitis.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specify a diagnostic test that is commonly used in the assessment of patients with prostatism.
* **Option B:** This option is incorrect because while serum prostate-specific antigen (PSA) levels may be elevated in patients with prostatism, they are not a direct assessment of the patient's symptoms.
* **Option C:** This option is incorrect because it is a treatment option for patients with prostatism, rather than a diagnostic test.

**Clinical Pearl / High-Yield Fact**
It is essential to note that patients with prostatism may also experience symptoms of urinary retention, nocturia, and hematuria, which can impact their quality of life. A thorough medical history and physical examination are crucial in differentiating between these symptoms and identifying the underlying cause.

**Correct Answer:** D