What does the abbreviation "r/o" stand for in a medical context?

In a medical context, the abbreviation "r/o" stands for "rule out." This term is commonly used by healthcare professionals to indicate that a particular diagnosis or condition is being considered and that further tests or evaluations are needed to either confirm or exclude it. For example, if a doctor states they need to "r/o pneumonia," they mean they need to conduct tests to determine if pneumonia is present or not.

The choice "without" is not an accurate representation of what "r/o" signifies in a medical setting. Similarly, the other options do not align with the established usage of the abbreviation in clinical documentation and communication. Therefore, the correct interpretation of "r/o" as "rule out" is essential for understanding medical discussions and documentation.