Final answer:
A medical assistant should recognize urine analysis as a laboratory test when processing a patient's referral, as it provides detailed medical information from urine samples.
Step-by-step explanation:
When processing a patient's referral, a medical assistant should identify a urine analysis as a laboratory test. Options such as blood pressure monitoring, X-rays, and physical examinations, while important methods of assessment, do not fall under the category of laboratory tests. A urine analysis is a common laboratory test that can provide valuable medical information by examining the physical, chemical, and microscopic properties of urine. This test may reveal important clues about a person's health, including kidney function, and can detect the presence of proteins, red blood cells, and other significant markers.