Questions: Which of the following is a diagnostic test that measures the level of PSA in a Man's blood? Digital rectal exam Prostate biospsy Protein specific antigen Prostate-specific antigen

The answer is the fourth one: Prostate-specific antigen.

Explanation for each option:

1. Digital rectal exam: This is a physical examination where a doctor inserts a finger into the rectum to feel the prostate gland for abnormalities. It does not measure PSA levels.
2. Prostate biopsy: This is a procedure where small samples of prostate tissue are removed and examined for cancer cells. It does not measure PSA levels.
3. Protein specific antigen: This is incorrect because the correct term is "Prostate-specific antigen," not "Protein specific antigen."
4. Prostate-specific antigen: This is the correct answer. The PSA test measures the level of prostate-specific antigen in a man's blood, which can be an indicator of prostate health.

Summary: The diagnostic test that measures the level of PSA in a man's blood is the Prostate-specific antigen test.